Global Technical Regulation No. 11

Name:Global Technical Regulation No. 11
Description:Agricultural and Forestry Tractors and Non-road Mobile Machinery Engine Emissions.
Official Title:Engine Emissions from Agricultural and Forestry Tractors and from Non-road Mobile Machinery.
Country:ECE - United Nations
Date of Issue:2010-03-09
Amendment Level:Corrigendum 2 of April 30, 2012
Number of Pages:254
Vehicle Types:Agricultural Tractor, Component
Subject Categories:Emissions and Fuel Consumption
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Keywords:

flow, gas, exhaust, test, mass, paragraph, engine, air, system, rate, sample, concentration, speed, dilution, analyzer, mol, sampling, emission, measured, cycle, calibration, reference, time, values, verification, pressure, diluted, torque, calculated, fuel, molar, measurement, response, temperature, emissions, testing, fid, span, total, filter, factor, recorded, raw, determined, annex, ratio, maximum, basis, manufacturer, inlet

Text Extract:

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ECE/TRANS/180/Add.11/Corr.3
April 30, 2012
GLOBAL REGISTRY
Created on November 18, 2004, Pursuant to Article 6 of the
AGREEMENT CONCERNING THE ESTABLISHING OF GLOBAL TECHNICAL
REGULATIONS FOR WHEELED VEHICLES, EQUIPMENT AND PARTS WHICH
CAN BE FITTED AND/OR BE USED ON WHEELED VEHICLES
(ECE/TRANS/132 and Corr.1)
DONE AT GENEVA ON JUNE 25, 1998
Addendum:
GLOBAL TECHNICAL REGULATION NO. 11
TEST PROCEDURE FOR COMPRESSION-IGNITION ENGINES TO BE INSTALLED IN
AGRICULTURAL AND FORESTRY TRACTORS AND IN NON-ROAD MOBILE MACHINERY
WITH REGARD TO THE EMISSIONS OF POLLUTANTS BY THE ENGINE
(ESTABLISHED IN THE GLOBAL REGISTRY ON NOVEMBER 12, 2009)
Incorporating:
Corrigendum 1
dated October 28, 2011
Corrigendum 2
dated April 30, 2012

Annex A.7
Annex A.7 −
Annex A.7 −
Annex A.8
Annex A.8 −
Annex A.8 −
MOLAR BASED EMISSION CALCULATIONS
Appendix 1 DILUTED EXHAUST FLOW (CVS) CALIBRATION
Appendix 2 DRIFT CORRECTION
MASS BASED EMISSION CALCULATIONS
Appendix 1 DILUTED EXHAUST FLOW (CVS) CALIBRATION
Appendix 2 DRIFT CORRECTION

4. The test procedure reflects world-wide NRMM engine operation, as closely as possible,
and provides a marked improvement in the realism of the test procedure for measuring
the emission performance of existing and future NRMM engines. In summary, the test
procedure was developed so that it would be:
(a)
(b)
(c)
(d)
(e)
Representative of world-wide non-road mobile machinery engine operations;
Able to provide the highest possible level of efficiency in controlling non-road
mobile machinery engine emissions;
Corresponding to state-of-the-art testing, sampling and measurement technology;
Applicable in practice to existing and foreseeable future exhaust emissions
abatement technologies; and
Capable of providing a reliable ranking of exhaust emission levels from different
engine types.
5. At this stage, the gtr is being presented without limit values and the NRMM engines'
applicable power range. In this way, the test procedure can be given a legal status,
based on which the Contracting Parties are required to start the process of implementing
it into their national law. The gtr contains one option, the adoption of which is left to the
discretion of the Contracting Parties. This option is related to the allowed dilution air
temperature range.
6. When implementing the test procedure contained in this gtr as part of their national
legislation or regulation, Contracting Parties are invited to use limit values which
represent at least the same level of severity as their existing regulations, pending the
development of harmonized limit values by the Executive Committee (AC.3) of the 1998
Agreement administered by the World Forum for Harmonization of Vehicle Regulations
(WP.29). The performance levels (emissions test results) to be achieved in the gtr will,
therefore, be discussed on the basis of the most recently agreed legislation in the
Contracting Parties, as required by the 1998 Agreement.
7. In order to facilitate the regulatory activities of certain countries, in particular those that
have not yet enforced legislation in this field or whose legislation is not yet as rigorous as
the ones mentioned above, a guidance document is also available. The format is based
on the one used in the EU for New and Global Approach Directives. It is important to
note that only the text of the gtr is legally binding. The guidance document has no legal
status and it does not introduce any additional requirements but aims at facilitating the
use of the gtr and to help in applying the gtr. The guidance document is placed side by
side with the gtr at the UNECE WP.29 website as already agreed by AC.3.

2. APPLICATION/SCOPE
This regulation applies to the determination of the emissions of pollutants of
compression-ignition (C.I.) engines with a maximum power not smaller that 19 kW and
not larger than 560 kW to be used:
(a) In Category T vehicles ;
(b)
In non-road mobile machinery.
3. DEFINITIONS, SYMBOLS AND ABBREVIATIONS
3.1. Definitions
3.1.1. "Adjustment factors" mean additive (upward adjustment factor and downward
adjustment factor) or multiplicative factors to be considered during the periodic
(infrequent) regeneration;
3.1.2. "Applicable emission limit" means an emission limit to which an engine is subject;
3.1.3. "Aqueous condensation" means the precipitation of water-containing constituents from
a gas phase to a liquid phase. Aqueous condensation is a function of humidity,
pressure, temperature, and concentrations of other constituents such as sulphuric acid.
These parameters vary as a function of engine intake-air humidity, dilution-air humidity,
engine air-to-fuel ratio, and fuel composition - including the amount of hydrogen and
sulphur in the fuel;
3.1.4. "Atmospheric pressure" means the wet, absolute, atmospheric static pressure. Note
that if the atmospheric pressure is measured in a duct, negligible pressure losses shall
be ensured between the atmosphere and the measurement location, and changes in the
duct's static pressure resulting from the flow shall be accounted for;
3.1.5. "Calibration" means the process of setting a measurement system's response so that
its output agrees with a range of reference signals. Contrast with "verification";
3.1.6. "Calibration gas" means a purified gas mixture used to calibrate gas analyzers.
Calibration gases shall meet the specifications of 9.5.1. Note that calibration gases and
span gases are qualitatively the same, but differ in terms of their primary function.
Various performance verification checks for gas analyzers and sample handling
components might refer to either calibration gases or span gases;
3.1.7. "Certification" means relating to the process of obtaining a certificate of conformity;
3.1.8. "Constant-speed engine" means an engine whose type approval or certification is
limited to constant speed operation. Engines whose constant-speed governor function is
removed or disabled are no longer constant-speed engines;

3.1.20. "Engine governed speed" means the engine operating speed when it is controlled by
the installed governor;
3.1.21. "Engine system" means the engine, the emission control system and the
communication interface (hardware and messages) between the engine system
electronic control unit(s) (ECU) and any other powertrain or vehicle control unit;
3.1.22. "Engine type" means a category of engines which do not differ in essential engine
characteristics;
3.1.23. "Exhaust after-treatment system" means a catalyst, particulate filter, deNO system,
combined deNO particulate filter or any other emission-reducing device that is installed
downstream of the engine. This definition excludes exhaust gas recirculation (EGR) and
turbochargers, which are considered an integral part of the engine;
3.1.24. "Exhaust-gas recirculation" means a technology that reduces emissions by routing
exhaust gases that had been exhausted from the combustion chamber(s) back into the
engine to be mixed with incoming air before or during combustion. The use of valve
timing to increase the amount of residual exhaust gas in the combustion chamber(s) that
is mixed with incoming air before or during combustion is not considered exhaust-gas
recirculation for the purposes of this regulation;
3.1.25. "Full flow dilution method" means the process of mixing the total exhaust flow with
dilution air prior to separating a fraction of the diluted exhaust stream for analysis;
3.1.26. "Gaseous pollutants" means carbon monoxide, hydrocarbons and/or non-methane
hydrocarbons (assuming a ratio of CH for diesel), methane and oxides of nitrogen
(expressed as nitrogen dioxide (NO ) equivalent);
3.1.27. "Good engineering judgment" means judgments made consistent with generally
accepted scientific and engineering principles and available relevant information;
3.1.28. "HEPA filter" means high-efficiency particulate air filters that are rated to achieve a
minimum initial particle-removal efficiency of 99.97% using ASTM F 1471–93 or
equivalent standard;
3.1.29. "Hydrocarbon (HC)" means THC, NMHC as applicable. Hydrocarbon generally means
the hydrocarbon group on which the emission standards are based for each type of fuel
and engine;
3.1.30. "High speed (n )" means the highest engine speed where 70% of the maximum power
occurs;
3.1.31. "Idle speed" means the lowest engine speed with minimum load (greater than or equal
to zero load), where an engine governor function controls engine speed. For engines
without a governor function that controls idle speed, idle speed means the manufacturerdeclared
value for lowest engine speed possible with minimum load. Note that warm idle
speed is the idle speed of a warmed-up engine;

3.1.43. "Partial pressure" means the pressure, p, attributable to a single gas in a gas mixture.
For an ideal gas, the partial pressure divided by the total pressure is equal to the
constituent's molar concentration, x;
3.1.44. "Particulate after-treatment device" means an exhaust after-treatment system
designed to reduce emissions of particulate pollutants (PM) through a mechanical,
aerodynamic, diffusional or inertial separation;
3.1.45. "Partial flow dilution method" means the process of separating a part from the total
exhaust flow, then mixing it with an appropriate amount of dilution air prior to the
particulate sampling filter;
3.1.46. "Particulate matter (PM)" means any material collected on a specified filter medium
after diluting exhaust with clean filtered air to a temperature and a point as specified in
Paragraph 9.3.3.4.; this is primarily carbon, condensed hydrocarbons, and sulphates
with associated water;
3.1.47. "Penetration fraction PF" means the deviation from ideal functioning of a non-methane
cutter (see Conversion efficiency of non-methane cutter (NMC) E). An ideal
non-methane cutter would have a methane penetration factor, PF , of 1.000 (that is, a
methane conversion efficiency E of 0), and the penetration fraction for all other
hydrocarbons would be 0.000, as represented by PF (that is, an ethane conversion
efficiency E of 1). The relationship is: PF = 1 – E and PF = 1 – E ;
3.1.48. "Per cent load" means the fraction of the maximum available torque at an engine
speed;
3.1.49. "Periodic (or infrequent) regeneration" means the regeneration process of an exhaust
after-treatment system that occurs periodically in typically less than 100 hours of normal
engine operation. During cycles where regeneration occurs, emission standards may be
exceeded;
3.1.50. "Probe" means the first section of the transfer line which transfers the sample to next
component in the sampling system;
3.1.51. "PTFE" means polytetrafluoroethylene, commonly known as Teflon ;
3.1.52. "Ramped modal steady state test cycle" means a test cycle with a sequence of
steady state engine test modes with defined speed and torque criteria at each mode and
defined speed and torque ramps between these modes;
3.1.53. "Rated speed" means the maximum full load speed allowed by the governor, as
designed by the manufacturer, or, if such a governor is not present, the speed at which
the maximum power is obtained from the engine, as designed by the manufacturer;
3.1.54. "Regeneration" means an event during which emissions levels change while the aftertreatment
performance is being restored by design. Two types of regeneration can
occur: continuous regeneration (see Paragraph 6.6.1.) and infrequent (periodic)
regeneration (see Paragraph 6.6.2.);

3.1.68. "Tolerance" means the interval in which 95% of a set of recorded values of a certain
quantity shall lie, with the remaining 5% of the recorded values deviating from the
tolerance interval. The specified recording frequencies and time intervals shall be used
to determine if a quantity is within the applicable tolerance.
3.1.69. "Total hydrocarbon (THC)" means the combined mass of organic compounds
measured by the specified procedure for measuring total hydrocarbon, expressed as a
hydrocarbon with a hydrogen-to-carbon mass ratio of 1.85:1;
3.1.70. "Transformation time" means the difference in time between the change of the
component to be measured at the reference point and a system response of 50% of the
final reading (t ) with the sampling probe being defined as the reference point. The
transformation time is used for the signal alignment of different measurement
instruments. See Figure 3.1;
3.1.71. "Transient test cycle" means a test cycle with a sequence of normalized speed and
torque values that vary relatively quickly with time (NRTC);
3.1.72. "Type approval" means the approval of an engine type with regard to its emissions
measured in accordance with the procedures specified in this regulation;
3.1.73. "Updating-recording" means the frequency at which the analyser provides new,
current, values;
3.1.74. "Useful life" means the relevant period of distance and/or time over which compliance
with the relevant gaseous and particulate emission limits has to be assured;
3.1.75. "Variable-speed engine" means an engine that is not a constant-speed engine;
3.1.76. "Verification" means to evaluate whether or not a measurement system's outputs agree
with a range of applied reference signals to within one or more predetermined thresholds
for acceptance. Contrast with "calibration";
3.1.77. "To zero" means to adjust an instrument so it gives a zero response to a zero calibration
standard, such as purified nitrogen or purified air for measuring concentrations of
emission constituents;
3.1.78. "Zero gas" means a gas that yields a zero response in an analyzer. This may either be
purified nitrogen, purified air, a combination of purified air and purified nitrogen.

Symbol Unit Term
L
-
% torque
M
g/mol
Molar mass of the intake air
M
g/mol
Molar mass of the exhaust
M
g/mol
Molar mass of gaseous components
m
kg
Mass
m
g
Mass of gaseous emissions over the test cycle
m
g
Mass of particulate emissions over the test cycle
n
min
Engine rotational speed
n
min
High engine speed
n
min
Low engine speed
P
kW
Power
P
kW
Maximum observed or declared power at the test speed
under the test conditions (specified by the manufacturer)
P
kW
Declared total power absorbed by auxiliaries fitted for the
test
p
kPa
Pressure
p
kPa
Dry atmospheric pressure
P
%
Penetration fraction
q
kg/s
Intake air mass flow rate on wet basis
q
kg/s
Dilution air mass flow rate on wet basis
q
kg/s
Diluted exhaust gas mass flow rate on wet basis
q
kg/s
Exhaust gas mass flow rate on wet basis
q
kg/s
Fuel mass flow rate
q
kg/s
Sample flow of exhaust gas into partial flow dilution system
q
m³/s
Volume flow rate
RF
-
Response factor
r
-
Dilution ratio
r
-
Coefficient of determination
Ρ
kg/m³
Density
σ
-
Standard deviation
S
kW
Dynamometer setting
SEE
-
Standard error of estimate of y on x
T
°C
Temperature
T
K
Absolute temperature
T
N·m
Engine torque
T
N·m
Demanded torque with "sp" set-point
u
-
Ratio between densities of gas component and exhaust gas
t
s
Time
Δt
s
Time interval
t
s
Time between step input and 10% of final reading
t
s
Time between step input and 50% of final reading
t
s
Time between step input and 90% of final reading
V
m
Volume
W
kWh
Work
y
Generic variable
y
Arithmetic mean

NMHC
NO
NO
NO
PM
S
THC
Non-methane hydrocarbon
Oxides of nitrogen
Nitric oxide
Nitrogen dioxide
Particulate matter
Sulphur
Total hydrocarbon
3.5.
Abbreviations
ASTM
American Society for Testing and Materials
BMD
Bag mini-diluter
BSFC
Brake-specific fuel consumption
CFV
Critical Flow Venturi
CI
Compression-ignition
CLD
Chemiluminescent Detector
CVS
Constant Volume Sampler
deNO
NO after-treatment system
DF
Deterioration factor
ECM
Electronic control module
EFC
Electronic flow control
EGR
Exhaust gas recirculation
FID
Flame Ionization Detector
GC
Gas Chromatograph
HCLD
Heated Chemiluminescent Detector
HFID
Heated Flame Ionization Detector
IBP
Initial boiling point
ISO
International Organization for Standardization
LPG
Liquefied Petroleum Gas
NDIR
Nondispersive infrared (Analyzer)
NDUV
Nondispersive ultraviolet (Analyzer)
NIST
US National Institute for Standards and Technology
NMC
Non-Methane Cutter
PDP
Positive Displacement Pump
% FS
% of full scale
PFD
Partial Flow Dilution
PFS
Partial Flow System
PTFE
Polytetrafluoroethylene (commonly known as Teflon™)
RMC
Ramped-modal cycle
RMS
Root-mean square
RTD
Resistive temperature detector
SAE
Society of Automotive Engineers
SSV
Subsonic Venturi
UCL
Upper confidence limit
UFM
Ultrasonic flow meter

5.1.3. Equivalency
The determination of system equivalency shall be based on a seven-sample pair
(or larger) correlation study between the system under consideration and one of the
systems of this gtr.
"Results" refer to the specific cycle weighted emissions value. The correlation testing is
to be performed at the same laboratory, test cell, and on the same engine, and is
preferred to be run concurrently. The equivalency of the sample pair averages shall be
determined by F-test and t-test statistics as described in Annex A.2. obtained under the
laboratory test cell and the engine conditions described above. Outliers shall be
determined in accordance with ISO 5725 and excluded from the database. The systems
to be used for correlation testing shall be subject to the approval by the type approval or
certification authority.
5.2. Engine Family
5.2.1. General
An engine family is characterized by design parameters. These shall be common to all
engines within the family. The engine manufacturer may decide, which engines belong
to an engine family, as long as the membership criteria listed in Paragraph 5.2.3. are
respected. The engine family shall be approved by the type approval or certification
authority. The manufacturer shall provide to the type approval or certification authority
the appropriate information relating to the emission levels of the members of the engine
family. For purposes of certification or type approval, the Contracting Party may have
additional requirements for engine family definition based upon engine power, fuel type
and emission limits.
5.2.2. Special Cases
5.2.2.1. Interactions Between Parameters
In some cases there may be interaction between parameters, which may cause
emissions to change. This shall be taken into consideration to ensure that only engines
with similar exhaust emission characteristics are included within the same engine family.
These cases shall be identified by the manufacturer and notified to the type approval or
certification authority. It shall then be taken into account as a criterion for creating a new
engine family.
5.2.2.2. Devices or Features Having a Strong Influence on Emissions
In case of devices or features, which are not listed in Paragraph 5.2.3. and which have a
strong influence on the level of emissions, this equipment shall be identified by the
manufacturer using good engineering judgment, and shall be notified to the type
approval or certification authority. It shall then be taken into account as a criterion for
creating a new engine family.

5.2.3.5. Method of Air Aspiration
(a)
(b)
(c)
Naturally aspirated;
Pressure charged;
Pressure charged with charge cooler.
5.2.3.6. Combustion Chamber Type/Design
(a)
(b)
(c)
Open chamber;
Divided chamber;
Other types.
5.2.3.7. Valves and Porting
(a)
(b)
Configuration;
Number of valves per cylinder.
5.2.3.8. Fuel Supply Type
(a)
(b)
(c)
(d)
Pump, (high pressure) line and injector;
In-line pump or distributor pump;
Unit injector;
Common rail.
5.2.3.9. Miscellaneous Devices
(a)
(b)
(c)
(d)
Exhaust gas recirculation (EGR);
Water injection;
Air injection;
Others.
5.2.3.10. Electronic Control Strategy
The presence or absence of an electronic control unit (ECU) on the engine is
regarded as a basic parameter of the family.
In the case of electronically controlled engines, the manufacturer shall present the
technical elements explaining the grouping of these engines in the same family,
i.e. the reasons why these engines can be expected to satisfy the same emission
requirements.

If engines within the family incorporate other variable features which may be considered
to affect exhaust emissions, these features shall also be identified and taken into
account in the selection of the parent engine.
If engines within the family meet the same emission values over different useful life
periods, this shall be taken into account in the selection of the parent engine.
5.3. Record Keeping
Record keeping requirements to be decided by the Contracting Parties. The procedures
in this gtr include various requirements to record data or other information.
6. TEST CONDITIONS
6.1. Laboratory Test Conditions
The absolute temperature (T ) of the engine air at the inlet to the engine expressed in
Kelvin, and the dry atmospheric pressure (p ), expressed in kPa shall be measured and
the parameter f shall be determined according to the following provisions. In
multi-cylinder engines having distinct groups of intake manifolds, such as in a "V" engine
configuration, the average temperature of the distinct groups shall be taken. The
parameter f shall be reported with the test results. For better repeatability and
reproducibility of the test results, it is recommended that the parameter f be such that:
0.93 ≤ f ≤ 1.07. Contracting Parties can make the parameter f compulsory.
Naturally aspirated and mechanically supercharged engines:
ƒ
⎛ 99 ⎞ ⎛ T ⎞
=

⎟ × ⎜ ⎟
⎝ ρ ⎠ ⎝ 298 ⎠
(6-1)
Turbocharged engines with or without cooling of the intake air:
ƒ
⎛ 99 ⎞
=


⎝ ρ ⎠
⎛ T ⎞
× ⎜ ⎟
⎝ 298 ⎠
(6-2)
The temperature of intake air shall be maintained to (25 ± 5) °C, as measured upstream
of any engine component.
It is allowed to use:
(a)
(b)
A shared atmospheric pressure meter as long as the equipment for handling
intake air maintains ambient pressure, where the engine is tested, within ± 1 kPa
of the shared atmospheric pressure;
A shared humidity measurement for intake air as long as the equipment for
handling intake air maintains dew point, where the engine is tested, within ± 0.5 °C
of the shared humidity measurement.

6.3.3. Auxiliaries to be Removed
Certain auxiliaries whose definition is linked with the operation of the machine and which
may be mounted on the engine shall be removed for the test.
Where auxiliaries cannot be removed, the power they absorb in the unloaded condition
may be determined and added to the measured engine power (see note g in the table of
Annex A.5). If this value is greater than 3% of the maximum power at the test speed it
may be verified by the test authority. The power absorbed by auxiliaries shall be used to
adjust the set values and to calculate the work produced by the engine over the test
cycle.
6.4. Engine Intake Air
6.4.1. Introduction
The intake-air system installed on the engine or one that represents a typical in-use
configuration shall be used. This includes the charge-air cooling and exhaust gas
recirculation systems.
6.4.2. Intake Air Restriction
An engine air intake system or a test laboratory system shall be used presenting an air
intake restriction within ± 300 Pa of the maximum value specified by the manufacturer for
a clean air cleaner at the rated speed and full load. The static differential pressure of the
restriction shall be measured at the location and at the speed and torque set-points
specified by the manufacturer. If the manufacturer does not specify a location, this
pressure shall be measured upstream of any turbocharger or exhaust gas recirculation
system connection to the intake air system. If the manufacturer does not specify speed
and torque points, this pressure shall be measured while the engine outputs maximum
power.
6.5. Engine Exhaust System
The exhaust system installed with the engine or one that represents a typical in-use
configuration shall be used. For after-treatment devices the exhaust restriction shall be
defined by the manufacturer according to the after-treatment condition
(e.g. degreening/aging and regeneration/loading level). The exhaust system shall
conform to the requirements for exhaust gas sampling, as set out in Paragraph 9.3. An
engine exhaust system or a test laboratory system shall be used presenting a static
exhaust backpressure within 80 to 100% of the maximum exhaust restriction at the
engine speed and torque specified by the manufacturer. If the maximum restriction is
5 kPa or less, the set-point shall be no less than 1.0 kPa from the maximum. If the
manufacturer does not specify speed and torque points, this pressure shall be measured
while the engine produces maximum power.

6.6.2. Periodic (Infrequent) Regeneration
This provision only applies for engines equipped with emission controls that are
regenerated on a periodic basis. For engines which are run on the discrete mode cycle
this procedure cannot be applied.
The emissions shall be measured on at least three NRTC hot start tests or
ramped-modal cycle (RMC) tests, one with and two without a regeneration event on a
stabilized after-treatment system. The regeneration process shall occur at least once
during the NRTC or RMC test. If regeneration takes longer than one NRTC or RMC test,
consecutive NRTC or RMC tests shall be run and emissions continued to be measured
without shutting the engine off until regeneration is completed and the average of the
tests shall be calculated. If regeneration is completed during any test, the test shall be
continued over its entire length. The engine may be equipped with a switch capable of
preventing or permitting the regeneration process provided this operation has no effect
on the original engine calibration.
The manufacturer shall declare the normal parameter conditions under which the
regeneration process occurs (soot load, temperature, exhaust back-pressure, etc.). The
manufacturer shall also provide the frequency of the regeneration event in terms of
number of tests during which the regeneration occurs. The exact procedure to
determine this frequency shall be agreed by the type approval or certification authority
based upon good engineering judgement.
For a regeneration test, the manufacturer shall provide an after-treatment system that
has been loaded. Regeneration shall not occur during this engine conditioning phase.
As an option, the manufacturer may run consecutive NRTC hot start or RMC tests until
the after-treatment system is loaded. Emissions measurement is not required on all
tests.
Average emissions between regeneration phases shall be determined from the
arithmetic mean of several approximately equidistant NRTC hot start or RMC tests. As a
minimum, at least one hot NRTC or RMC as close as possible prior to a regeneration
test and one hot NRTC or RMC immediately after a regeneration test shall be conducted.
During the regeneration test, all the data needed to detect regeneration shall be
recorded (CO or NO emissions, temperature before and after the after-treatment
system, exhaust back pressure, etc.). During the regeneration process, the applicable
emission limits may be exceeded. The test procedure is schematically shown in
Figure 6.1.

At the choice of the manufacturer and based on upon good engineering analysis, the
regeneration adjustment factor k , expressing the average emission rate, may be
calculated either multiplicative or additive as follows:
Multiplicative
e
k = (upward adjustment factor) (6-4a)
e
e
k = (downward adjustment factor) (6-4b)
e
Additive
k =
k =
e − e (upward adjustment factor) (6-5)
e − e (downward adjustment factor) (6-6)
Upward adjustment factors are multiplied with or added to measured emission rates for
all tests in which the regeneration does not occur. Downward adjustment factors are
multiplied with or added to measured emission rates for all tests in which the
regeneration occurs. The occurrence of the regeneration shall be identified in a manner
that is readily apparent during all testing. Where no regeneration is identified, the
upward adjustment factor shall be applied.
With reference to Annexes A.7.-8. on brake specific emission calculations, the
regeneration adjustment factor:
(a)
(b)
(c)
(d)
Shall be applied to the results of the weighted NRTC and RMC tests, and discrete
mode cycle;
May be applied to the ramped modal cycles and cold NRTC, if a regeneration
occurs during the cycle;
May be extended to other members of the same engine family;
May be extended to other engine families using the same after-treatment system
with the prior approval of the type approval or certification authority based on
technical evidence to be supplied by the manufacturer that the emissions are
similar.

6.10. Crankcase Emissions
No crankcase emissions shall be discharged directly into the ambient atmosphere, with
the following exception: engines equipped with turbochargers, pumps, blowers, or
superchargers for air induction may discharge crankcase emissions to the ambient
atmosphere if the emissions are added to the exhaust emissions (either physically or
mathematically) during all emission testing. Manufacturers taking advantage of this
exception shall install the engines so that all crankcase emission can be routed into the
emissions sampling system. For the purpose of this paragraph, crankcase emissions
that are routed into the exhaust upstream of exhaust after-treatment during all operation
are not considered to be discharged directly into the ambient atmosphere.
Open crankcase emissions shall be routed into the exhaust system for emission
measurement, as follows:
(a)
(b)
(c)
(d)
The tubing materials shall be smooth-walled, electrically conductive, and not
reactive with crankcase emissions. Tube lengths shall be minimized as far as
possible;
The number of bends in the laboratory crankcase tubing shall be minimized, and
the radius of any unavoidable bend shall be maximized;
The laboratory crankcase exhaust tubing shall meet the engine manufacturer's
specifications for crankcase back pressure;
The crankcase exhaust tubing shall connect into the raw exhaust downstream of
any after-treatment system, downstream of any installed exhaust restriction, and
sufficiently upstream of any sample probes to ensure complete mixing with the
engine's exhaust before sampling. The crankcase exhaust tube shall extend into
the free stream of exhaust to avoid boundary-layer effects and to promote mixing.
The crankcase exhaust tube's outlet may orient in any direction relative to the raw
exhaust flow.

7.2.1.2. Batch Sampling
In batch sampling, a sample of raw or dilute exhaust is continuously extracted and stored
for later measurement. The extracted sample shall be proportional to the raw or dilute
exhaust flow rate. Examples of batch sampling are collecting diluted gaseous emissions
in a bag and collecting PM on a filter. In principal the method of emission calculation is
done as follows: the batch sampled concentrations are multiplied by the total mass or
mass flow (raw or dilute) from which it was extracted during the test cycle. This product
is the total mass or mass flow of the emitted constituent. To calculate the PM
concentration, the PM deposited onto a filter from proportionally extracted exhaust shall
be divided by the amount of filtered exhaust.
7.2.1.3. Combined Sampling
Any combination of continuous and batch sampling is permitted (e.g. PM with batch
sampling and gaseous emissions with continuous sampling).
The following Figure 7.1 illustrates the two aspects of the test procedures for measuring
emissions: the equipments with the sampling lines in raw and diluted exhaust gas and
the operations requested to calculate the pollutant emissions in steady-state and
transient test cycles (Figure 7.1).
Figure 7.1
Test Procedures for Emission Measurement
Note on Figure 7.1: The term "Partial flow PM sampling" includes the partial flow
dilution to extract only raw exhaust with constant or varying dilution ratio.

(h)
(i)
(j)
Exhaust dilution system flow shall be switched on at least 10 minutes before a test
sequence;
Calibration of gas analyzers and zeroing of continuous analyzers shall be carried
out according to the procedure of the next Paragraph 7.3.1.4;
Any electronic integrating devices shall be zeroed or re-zeroed, before the start of
any test interval.
7.3.1.4. Calibration of Gas Analyzers
Appropriate gas analyzer ranges shall be selected. Emission analyzers with automatic or
manual range switching are allowed. During a ramped modal or a NRTC test and during
a sampling period of a gaseous emission at the end of each mode for discrete mode
testing, the range of the emission analyzers may not be switched. Also the gains of an
analyzer's analogue operational amplifier(s) may not be switched during a test cycle.
All continuous analyzers shall be zeroed and spanned using internationally-traceable
gases that meet the specifications of Paragraph 9.5.1. FID analyzers shall be spanned
on a carbon number basis of one (C1).
7.3.1.5. PM Filter Preconditioning and Tare Weighing
The procedures for PM filter preconditioning and tare weighing shall be followed
according to Paragraph 8.2.3.
7.3.2. Post-Test Procedures
The following steps shall be taken after emission sampling is complete:
7.3.2.1. Verification of Proportional Sampling
For any proportional batch sample, such as a bag sample or PM sample, it shall be
verified that proportional sampling was maintained according to Paragraph 8.2.1. For
the single filter method and the discrete steady-state test cycle, effective PM weighting
factor shall be calculated. Any sample that does not fulfil the requirements of
Paragraph 8.2.1. shall be voided.
7.3.2.2. Post-Test PM Conditioning and Weighing
Used PM sample filters shall be placed into covered or sealed containers or the filter
holders shall be closed, in order to protect the sample filters against ambient
contamination. Thus protected, the loaded filters have to be returned to the PM-filter
conditioning chamber or room. Then the PM sample filters shall be conditioned and
weighted accordingly to Paragraph 8.2.4. (PM filter post-conditioning and total weighing
procedures).

7.4.1.1. Steady-State Discrete Mode Test Cycles
The steady-state discrete 8-mode test cycle consists of eight speed and load modes
(with the respective weighing factor for each mode) which cover the typical operating
range of variable speed engines. The cycle is shown in Annex A.1.
The steady-state discrete 5-mode constant-speed test cycle consists of five load modes
(with the respective weighing factor for each mode) all at rated speed which cover the
typical operating range of constant speed engines. The cycle is shown in Annex A.1.
7.4.1.2. Steady-State Ramped Test Cycles
The ramped modal test cycles (RMC) are hot running cycles where emissions shall be
started to be measured after the engine is started, warmed up and running as specified
in Paragraph 7.8.2.1. The engine shall be continuously controlled by the test bed control
unit during the RMC test cycle. The gaseous and particulate emissions shall be
measured and sampled continuously during the RMC test cycle in the same way as in a
transient cycle.
In case of the 5-mode test cycle the RMC consists of the same modes in the same order
as the corresponding discrete steady-state test cycle. For the 8-mode test cycle the
RMC has one mode more (split idle mode) and the mode sequence is not the same as
the corresponding steady-state discrete mode cycle, in order to avoid extreme changes
in the after-treatment temperature. The length of the modes shall be selected to be
equivalent to the weighting factors of the corresponding discrete steady-state test cycle.
The change in engine speed and load from one mode to the next one has to be linearly
controlled in a time of 20 ± 1 seconds. The mode change time is part of the new mode
(including the first mode).
7.4.2. Transient Test Cycle (NRTC)
The Non-Road Transient Cycle (NRTC) is specified in Annex A.1. as a
second-by-second sequence of normalized speed and torque values. In order to
perform the test in an engine test cell, the normalized values shall be converted to their
equivalent reference values for the individual engine to be tested, based on specific
speed and torque values identified in the engine-mapping curve. The conversion is
referred to as denormalization, and the resulting test cycle is the reference NRTC test
cycle of the engine to be tested (see Paragraph 7.7.2.).

(c)
The hot-start shall be started immediately after the soak period with the cranking
of the engine. The gaseous analyzers shall be switched on at least 10 seconds
before the end of the soak period to avoid switching signal peaks. The
measurement of emissions shall be started in parallel with the start of the hot start
phase including the cranking of the engine.
Brake specific emissions expressed in (g/kWh) shall be determined by using the
procedures of this section for both the cold and hot start test cycles. Composite
weighted emissions shall be computed by weighting the cold start results by 10% and
the hot start results by 90% as detailed in Annexes A.7.-A.8.
7.5. General Test Sequence
To measure engine emissions the following steps have to be performed:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
The engine test speeds and test loads have to be defined for the engine to be
tested by measuring the max torque (for constant speed engines) or max torque
curve (for variable speed engines) as function of the engine speed;
Normalized test cycles have to be denormalized with the torque (for constant
speed engines) or speeds and torques (for variable speed engines) found in the
previous Paragraph 7.5. (a);
The engine, equipment, and measurement instruments shall be prepared for the
following emission test or test series (cold and hot cycle) in advance;
Pre-test procedures shall be performed to verify proper operation of certain
equipment and analyzers. All analysers have to be calibrated. All pre-test data
shall be recorded;
The engine shall be started (NRTC) or kept running (steady-state cycles) at the
beginning of the test cycle and the sampling systems shall be started at the same
time;
Emissions and other required parameters shall be measured or recorded during
sampling time (for NRTC and steady-state ramped modal cycles throughout the
whole test cycle;
Post-test procedures shall be performed to verify proper operation of certain
equipment and analyzers;
(h) PM filter(s) shall be pre-conditioned, weighed (empty weight), loaded,
reconditioned, again weighed (loaded weight) and then samples shall be
evaluated according to pre- (7.3.1.5.) and post-test (7.3.2.2.) procedures;
(i)
Emission test results shall be evaluated.

7.5.1. Engine Starting, and Restarting
7.5.1.1. Engine Start
The engine shall be started:
(a)
(b)
As recommended in the owner's manual using a production starter motor or
air-start system and either an adequately charged battery, a suitable power supply
or a suitable compressed air source; or
By using the dynamometer to crank the engine until it starts. Typically motor the
engine within ± 25% of its typical in-use cranking speed or start the engine by
linearly increasing the dynamometer speed from zero to 100 min below low idle
speed but only until the engine starts.
Cranking shall be stopped within 1 s of starting the engine. If the engine does not start
after 15 s of cranking, cranking shall be stopped and the reason for the failure to start
determined, unless the owner's manual or the service-repair manual describes a longer
cranking time as normal.
7.5.1.2. Engine Stalling
(a)
(b)
(c)
If the engine stalls anywhere during the cold start test of the NRTC, the test shall
be voided;
If the engine stalls anywhere during the hot start test of the NRTC, the test shall
be voided. The engine shall be soaked according to Paragraph 7.8.3., and the hot
start test repeated. In this case, the cold start test does not need to be repeated;
If the engine stalls anywhere during the steady-state cycle (discrete or ramped),
the test shall be voided and be repeated beginning with the engine warm-up
procedure. In the case of PM measurement utilizing the multi-filter method
(one sampling filter for each operating mode), the test shall be continued by
stabilizing the engine at the previous mode for engine temperature conditioning
and then initiating measurement with the mode where the engine stalled.
7.6. Engine Mapping
Before starting the engine mapping, the engine shall be warmed up and towards the end
of the warm up it shall be operated for at least 10 minutes at maximum power or
according to the recommendation of the manufacturer and good engineering judgment in
order to stabilize the engine coolant and lube oil temperatures. When the engine is
stabilized, the engine mapping shall be performed.
Except constant speed engines, engine mapping shall be performed with fully open fuel
lever or governor using discrete speeds in ascending order. The minimum and
maximum mapping speeds are defined as follows:
Minimum mapping speed = warm idle speed
Maximum mapping speed = n x 1.02 or speed where max torque drops off to zero,
whichever is smaller.

(c)
(d)
(e)
The engine speed shall be increased at an average rate of 8 ± 1 min /s or the
engine shall be mapped by using a continuous sweep of speed at a constant rate
such that it takes 4 to 6 min to sweep from minimum to maximum mapping speed.
The mapping speed range shall be started between warm idle and 95% of warm
idle and ended at the highest speed above maximum power at which less than
70% of maximum power occurs. If this highest speed is unsafe or
unrepresentative (e.g., for ungoverned engines), good engineering judgment shall
be used to map up to the maximum safe speed or the maximum representative
speed. Engine speed and torque points shall be recorded at a sample rate of at
least 1 Hz;
If a manufacturer believes that the above mapping techniques are unsafe or
unrepresentative for any given engine, alternate mapping techniques may be
used. These alternate techniques shall satisfy the intent of the specified mapping
procedures to determine the maximum available torque at all engine speeds
achieved during the test cycles. Deviations from the mapping techniques
specified in this paragraph for reasons of safety or representativeness shall be
approved by the type approval or certification authority along with the justification
for their use. In no case, however, the torque curve shall be run by descending
engine speeds for governed or turbocharged engines;
An engine need not be mapped before each and every test cycle. An engine shall
be remapped if:
(i)
(ii)
(iii)
An unreasonable amount of time has transpired since the last map, as
determined by good engineering judgement; or
Physical changes or recalibrations have been made to the engine which
potentially affect engine performance; or
The atmospheric pressure near the engine's air inlet is not within ± 5 kPa of
the value recorded at the time of the last engine map.
7.6.3. Engine Mapping for Constant-Speed Engines
(a)
(b)
(c)
The engine may be operated with a production constant-speed governor or a
constant-speed governor maybe simulated by controlling engine speed with an
operator demand control system. Either isochronous or speed-droop governor
operation shall be used, as appropriate;
With the governor or simulated governor controlling speed using operator demand,
the engine shall be operated at no-load governed speed (at high speed, not low
idle) for at least 15 seconds;
The dynamometer shall be used to increase torque at a constant rate. The map
shall be conducted such that it takes 2 to 4 min to sweep from no-load governed
speed to the maximum torque. During the engine mapping actual speed and
torque shall be recorded with at least 1 Hz;

During the test cycle, the engine shall be operated at the engine speeds and torques that
are defined in Annex A.1.
The maximum mapping torque values at the specified test speeds shall be derived from
the mapping curve (see Paragraph 7.6.1. or 7.6.2). "Measured" values are either directly
measured during the engine mapping process or they are determined from the engine
map. "Declared" values are specified by the manufacturer. When both measured and
declared values are available, declared values may be used instead of torques if they
don't deviate more than ± 2.5%. Otherwise, measured torques derived from the engine
mapping shall be used.
7.7.1.3. Generation of Steady-State 5-Mode Test Cycle (Discrete and Ramp Modal)
During the test cycle, the engine shall be operated at the engine speeds and torques that
are defined in Annex A.1. The maximum mapping torque value at the specified rated
speed (see Paragraph 7.7.1.1.) shall be used to generate the 5-mode test cycle. A warm
minimum torque that is representative of in-use operation may be declared. For
example, if the engine is typically connected to a machine that does not operate below a
certain minimum torque, this torque may be declared and used for cycle generation.
When both measured and declared values are available for the maximum test torque for
cycle generation, the declared value may be used instead of the measured value if it is
within 95 to 100% of the measured value.
The torque figures are percentage values of the torque corresponding to the prime
power rating. The prime power is defined as the maximum power available during a
variable power sequence, which may be run for an unlimited number of hours per year,
between stated maintenance intervals and under the stated ambient conditions. The
maintenance shall be carried out as prescribed by the manufacturer.
7.7.2. Generation of Transient Test Cycle (NRTC Denormalization)
Annex A.1. defines applicable test cycles in a normalized format. A normalized test
cycle consists of a sequence of paired values for speed and torque %.
Normalized values of speed and torque shall be transformed using the following
conventions:
(a)
(b)
(c)
The normalized speed shall be transformed into a sequence of reference speeds,
n , according to Paragraph 7.7.2.2;
The normalized torque is expressed as a percentage of the mapped torque at the
corresponding reference speed. These normalized values shall be transformed
into a sequence of reference torques, T , according to Paragraph 7.7.2.3;
The reference speed and reference torque values expressed in coherent units are
multiplied to calculate the reference power values.

7.7.2.2. Denormalization of Engine Speed
The engine speed shall be denormalized using the following equation:
( n − n )
% speed ⋅
n = + n
(7-4)
100
Where:
n = reference speed
n = denormalization speed
n = idle speed
%speed
= tabled NRTC normalized speed
7.7.2.3. Denormalization of Engine Torque
The torque values in the engine dynamometer schedule of Annex A.1.4. are normalized
to the maximum torque for the respective reference speed as determined in
Paragraph 7.7.2.2. The torque values of the reference cycle shall be denormalized,
using the mapping curve determined according to Paragraph 7.6.2., as follows:
T
%torque ⋅ max.torque
= (7-5)
100
7.7.2.4. Example of Denormalization Procedure
As an example, the following test point shall be denormalized:
% speed = 43%
% torque = 82%
Given the following values:
n = 2200 min
n = 600 min
results in
n
=
43 ⋅
( 2200 − 600)
100
+ 600 = 1288 min
With the maximum torque of 700 Nm observed from the mapping curve at 1288 min
T
82 × 700
=
100
= 574 Nm

(e)
(f)
If the engine stalls or the emission sampling is interrupted at any time after
emission sampling begins for a discrete mode and the single filter method, the test
shall be voided and be repeated beginning with the engine warm-up procedure. In
the case of PM measurement utilizing the multi-filter method (one sampling filter
for each operating mode), the test shall be continued by stabilizing the engine at
the previous mode for engine temperature conditioning and then initiating
measurement with the mode where the engine stalled;
Post-test procedures according to Paragraph 7.3.2. shall be performed.
7.8.1.3. Validation Criteria
During each mode of the given steady-state test cycle after the initial transition period,
the measured speed shall not deviate from the reference speed for more than ± 1% of
rated speed or ± 3 min , whichever is greater except for idle which shall be within the
tolerances declared by the manufacturer. The measured torque shall not deviate from
the reference torque for more than ± 2% of the maximum torque at the test speed.
7.8.2. Ramped Modal Test Cycles
7.8.2.1. Engine Warming-Up
Before starting the steady-state ramped modal test cycles (RMC), the engine shall be
warmed-up and running until engine temperatures (cooling water and lube oil) have been
stabilized on 50% speed and 50% torque for the RMC test cycle (derived from the
8-mode test cycle) and at rated or nominal engine speed and 50% torque for the RMC
test cycle (derived from 5-mode test cycle). Immediately after this engine conditioning
procedure, engine speed and torque shall be changed in a linear ramp of 20 ± 1 s to the
first mode of the test. In between 5 to 10 s after the end of the ramp, the test cycle
measurement shall start.
7.8.2.2. Performing a Ramped Modal Test Cycle
The ramped modal cycles derived from 8-mode and 5-mode test cycle are shown in
Annex A.1.
The engine shall be operated for the prescribed time in each mode. The transition from
one mode to the next shall be done linearly in 20 s ± 1 s following the tolerances
prescribed in Paragraph 7.8.2.4. (see Annex A.1.)
For ramped modal cycles, reference speed and torque values shall be generated at a
minimum frequency of 1 Hz and this sequence of points shall be used to run the cycle.
During the transition between modes, the denormalized reference speed and torque
values shall be linearly ramped between modes to generate reference points. The
normalized reference torque values shall not be linearly ramped between modes and
then denormalized. If the speed and torque ramp runs through a point above the
engine's torque curve, it shall be continued to command the reference torques and it
shall be allowed for the operator demand to go to maximum.

In case of running the RMC test not on a transient test bed, where the second by second
speed and torque values are not available, the following validation criteria shall be used.
At each mode the requirements for the speed and torque tolerances are given in
Paragraph 7.8.1.3. For the 20 s linear speed and linear torque transitions between the
RMC steady-state test modes (Paragraph 7.4.1.2.) the following tolerances for speed
and load shall be applied for the ramp, the speed shall be held linear within ± 2% of rated
speed. The torque shall be held linear within ± 5% of the maximum torque at rated
speed.
7.8.3. Transient Test Cycle (NRTC)
Reference speeds and torques commands shall be sequentially executed to perform the
transient test cycle. Speed and torque commands shall be issued at a frequency of at
least 5 Hz. Because the reference test cycle is specified at 1 Hz, the in between speed
and torque commands shall be linearly interpolated from the reference torque values
generated from cycle generation.
Small denormalized speed values near warm idle speed may cause low-speed idle
governors to activate and the engine torque to exceed the reference torque even though
the operator demand is at a minimum. In such cases, it is recommended to control the
dynamometer so it gives priority to follow the reference torque instead of the reference
speed and let the engine govern the speed.
Under cold-start conditions engines may use an enhanced-idle device to quickly warm
up the engine and after-treatment devices. Under these conditions, very low normalized
speeds will generate reference speeds below this higher enhanced idle speed. In this
case it is recommended controlling the dynamometer so it gives priority to follow the
reference torque and let the engine govern the speed when the operator demand is at
minimum.
During an emission test, reference speeds and torques and the feedback speeds and
torques shall be recorded with a minimum frequency of 1 Hz, but preferably of 5 Hz or
even 10 Hz. This larger recording frequency is important as it helps to minimize the
biasing effect of the time lag between the reference and the measured feedback speed
and torque values.
The reference and feedback speeds and torques maybe recorded at lower frequencies
(as low as 1 Hz), if the average values over the time interval between recorded values
are recorded. The average values shall be calculated based on feedback values
updated at a frequency of at least 5 Hz. These recorded values shall be used to
calculate cycle-validation statistics and total work.
7.8.3.1. Engine Preconditioning
To meet stable conditions for the following Emission test, the sampling system and the
engine shall be preconditioned either by driving a full pre-NRTC cycle or driving the
engine and the measuring systems under similar conditions as in the test cycle itself. If
the test before was also a NRTC hot test, no additional conditioning is needed.

7.8.3.5. Validation Statistics (see Annex A.2.)
Linear regression between the reference and the feedback values shall be calculated for
speed, torque and power.
To minimize the biasing effect of the time lag between the reference and feedback cycle
values, the entire engine speed and torque feedback signal sequence may be advanced
or delayed in time with respect to the reference speed and torque sequence. If the
feedback signals are shifted, both speed and torque shall be shifted by the same amount
in the same direction.
The method of least squares shall be used, with the best-fit equation having the form:
Where:
y = a x + a (7-6)
y
a
x
a
= feedback value of speed (min ), torque (Nm), or power (kW)
= slope of the regression line
= reference value of speed (min ), torque (Nm), or power (kW)
= y intercept of the regression line
The standard error of estimate (SEE) of y on x and the coefficient of determination (r²)
shall be calculated for each regression line (Annex A.2.).
It is recommended that this analysis be performed at 1 Hz. For a test to be considered
valid, the criteria of Table 7.2 of this paragraph shall be met.
Table 7.2
Regression Line Tolerances
Standard error of
estimate (SEE) of
y on x
Slope of the
regression line, a
Coefficient of
determination, r²
y intercept of the
regression line, a
Speed Torque Power
≤ 5.0% of maximum
test speed
≤ 10.0% of maximum
mapped torque
≤ 10.0% of maximum
mapped power
0.95 to 1.03 0.83 - 1.03 0.89 - 1.03
minimum 0.970 minimum 0.850 minimum 0.910
≤ 10% of idle
± 20 Nm or ± 2% of
maximum torque
whichever is greater
± 4 kW or ± 2% of
maximum power
whichever is greater

8.1.2. Summary of Calibration and Verification
The Table 8.1 summarizes the calibrations and verifications described in Paragraph 8.
and indicates when these have to be performed.
Table 8.1
Summary of Calibration and Verifications
Type of calibration
or verification
Minimum frequency
8.1.3: accuracy,
repeatability and
noise
Accuracy: Not required, but recommended for initial installation.
Repeatability: Not required, but recommended for initial installation.
Noise: Not required, but recommended for initial installation.
8.1.4: linearity Speed: Upon initial installation, within 370 days before testing and after major maintenance.
Torque: Upon initial installation, within 370 days before testing and after major maintenance.
Clean gas and diluted exhaust flows: Upon initial installation, within 370 days before testing
and after major maintenance, unless flow is verified by propane check or by carbon or oxygen
balance.
Raw exhaust flow: Upon initial installation, within 185 days before testing and after major
maintenance, unless flow is verified by propane check or by carbon or oxygen balance.
Gas analyzers: Upon initial installation, within 35 days before testing and after major
maintenance.
PM balance: Upon initial installation, within 370 days before testing and after major
maintenance.
Stand-alone pressure and temperature: Upon initial installation, within 370 days before testing
and after major maintenance.
8.1.5: Continuous
gas analyzer
system response
and
updating-recording
verification – for
gas analyzers not
continuously
compensated for
other gas species
8.1.6: Continuous
gas analyzer
system response
and
updating-recording
verification – for
gas analyzers
continuously
compensated for
other gas species
Upon initial installation or after system modification that would effect response.
Upon initial installation or after system modification that would effect response.
8.1.7.1: torque Upon initial installation and after major maintenance.
8.1.7.2: pressure,
temperature, dew
point
Upon initial installation and after major maintenance.

8.1.3. Verifications for Accuracy, Repeatability, and Noise
The performance values for individual instruments specified in Table 9.3 are the basis for
the determination of the accuracy, repeatability, and noise of an instrument.
It is not required to verify instrument accuracy, repeatability, or noise. However, it may
be useful to consider these verifications to define a specification for a new instrument, to
verify the performance of a new instrument upon delivery, or to troubleshoot an existing
instrument.
8.1.4. Linearity Check
8.1.4.1. Scope and Frequency
A linearity verification shall be performed on each measurement system listed in
Table 8.2 at least as frequently as indicated in the table, consistent with measurement
system manufacturer recommendations and good engineering judgment. The intent of a
linearity verification is to determine that a measurement system responds proportionally
over the measurement range of interest. A linearity verification shall consist of
introducing a series of at least 10 reference values to a measurement system, unless
otherwise specified. The measurement system quantifies each reference value. The
measured values shall be collectively compared to the reference values by using a least
squares linear regression and the linearity criteria specified in Table 8.2 of this
paragraph.
8.1.4.2. Performance Requirements
If a measurement system does not meet the applicable linearity criteria in Table 8.2, the
deficiency shall be corrected by re-calibrating, servicing, or replacing components as
needed. The linearity verification shall be repeated after correcting the deficiency to
ensure that the measurement system meets the linearity criteria.
8.1.4.3. Procedure
The following linearity verification protocol shall be used:
(a)
(b)
(c)
A measurement system shall be operated at its specified temperatures, pressures,
and flows;
The instrument shall be zeroed as it would before an emission test by introducing
a zero signal. For gas analyzers, a zero gas shall be used that meets the
specifications of Paragraph 9.5.1. and it shall be introduced directly at the analyzer
port;
The instrument shall be spanned as it would before an emission test by
introducing a span signal. For gas analyzers, a span gas shall be used that meets
the specifications of Paragraph 9.5.1. and it shall be introduced directly at the
analyzer port;

For temperature measurement systems with sensors like thermocouples, RTDs, and
thermistors, the linearity verification may be performed by removing the sensor from the
system and using a simulator in its place. A simulator that is independently calibrated
and cold junction compensated, as necessary shall be used. The internationally
traceable simulator uncertainty scaled to temperature shall be less than 0.5% of
maximum operating temperature T . If this option is used, it is necessary to use
sensors that the supplier states are accurate to better than 0.5% of T compared to
their standard calibration curve.
8.1.4.5. Measurement Systems that Require Linearity Verification
Table 8.2 indicates measurement systems that require linearity verifications. For this
table the following provisions apply.
(a)
(b)
A linearity verification shall be performed more frequently if the instrument
manufacturer recommends it or based on good engineering judgment;
"min" refers to the minimum reference value used during the linearity verification;0;
Note that this value may be zero or a negative value depending on the signal;
(c)
"max" generally refers to the maximum reference value used during the linearity
verification. For example for gas dividers, x is the undivided, undiluted, span
gas concentration. The following are special cases where "max" refers to a
different value:
(i)
For PM balance linearity verification, m
refers to the typical mass of a PM
filter;
(ii) For torque linearity verification, T refers to the manufacturer's specified
engine torque peak value of the highest torque engine to be tested;
(d) The specified ranges are inclusive. For example, a specified range of 0.98-1.02
for the slope a1 means 0.98 ≤ a ≤ 1.02;
(e)
(f)
These linearity verifications are not required for systems that pass the flow-rate
verification for diluted exhaust as described 8.1.8.5. for the propane check or for
systems that agree within ± 2% based on a chemical balance of carbon or oxygen
of the intake air, fuel, and exhaust;
a criteria for these quantities shall be met only if the absolute value of the quantity
is required, as opposed to a signal that is only linearly proportional to the actual
value;

Table 8.2. (continued)
Measurement
System
Quantity
Minimum
verification
frequency
X
( − 1)
Linearity Criteria
⋅ a + a a SEE r
Diluted exhaust
flow rate
Raw exhaust
flow rate
Batch sampler flow
rates
Gas dividers X/X
Gas analyzers
PM balance
Stand-alone
pressures
Analog-to-digital
conversion of
stand-alone
temperature
signals
q
q
q
x
m
p
T
Within 370 days
before testing
≤ 1% q
0.98-1.02
≤ 2% q
≥ 0.990
Within 185 days
before testing
≤ 1% q
0.98-1.02
≤ 2% q
≥ 0.990
Within 370 days
before testing
≤ 1% q
0.98-1.02
≤ 2% q
≥ 0.990
Within 370 days
before testing
≤ 0.5% x
0.98-1.02
≤ 2% x
≥ 0.990
Within 35 days
before testing
≤ 0.5% x
0.99-1.01
≤ 1% x
≥ 0.998
Within 370 days
before testing
≤ 1% m
0.99-1.01
≤ 1% m
≥ 0.998
Within 370 days
before testing
≤ 1% p
0.99-1.01
≤ 1% p
≥ 0.998
Within 370 days
before testing
≤ 1% T
0.99-1.01
≤ 1% T
≥ 0.998
8.1.5. Continuous Gas Analyser System-Response and Updating-Recording Verification
This section describes a general verification procedure for continuous gas analyzer
system response and update recording. See Paragraph 8.1.6. for verification
procedures for compensation type analysers.
8.1.5.1. Scope and Frequency
This verification shall be performed after installing or replacing a gas analyzer that is
used for continuous sampling. Also this verification shall be performed if the system is
reconfigured in a way that would change system response. This verification is needed
for continuous gas analysers used for transient or ramped-modal testing but is not
needed for batch gas analyzer systems or for continuous gas analyzer systems used
only for discrete-mode testing.

8.1.5.4. Procedure
The following procedure shall be used to verify the response of each continuous gas
analyzer system:
(a)
(b)
The analyzer system manufacturer's start-up and operating instructions for the
instrument setup shall be followed. The measurement system shall be adjusted
as needed to optimize performance. This verification shall be run with the
analyzer operating in the same manner as used for emission testing. If the
analyzer shares its sampling system with other analyzers, and if gas flow to the
other analyzers will affect the system response time, then the other analyzers shall
be started up and operated while running this verification test. This verification
test may be run on multiple analyzers sharing the same sampling system at the
same time. If analogue or real-time digital filters are used during emission testing,
those filters shall be operated in the same manner during this verification;
For equipment used to validate system response time, minimal gas transfer line
lengths between all connections are recommended to be used, a zero-air source
shall be connected to one inlet of a fast-acting 3-way valve (2 inlets, 1 outlet) in
order to control the flow of zero and blended span gases to the sample system's
probe inlet or a tee near the outlet of the probe. Normally the gas flow rate is
higher than the probe sample flow rate and the excess is overflowed out the inlet
of the probe. If the gas flow rate is lower than the probe flow rate, the gas
concentrations shall be adjusted to account for the dilution from ambient air drawn
into the probe. Binary or multi-gas span gases may be used. A gas blending or
mixing device may be used to blend span gases. A gas blending or mixing device
is recommended when blending span gases diluted in N with span gases diluted
in air;
Using a gas divider, an NO–CO–CO –C H –CH (balance N ) span gas shall be
equally blended with a span gas of NO , balance purified synthetic air. Standard
binary span gases may be also be used, where applicable, in place of blended
NO-CO-CO -C H -CH , balance N span gas; in this case separate response tests
shall be run for each analyzer. The gas divider outlet shall be connected to the
other inlet of the 3-way valve. The valve outlet shall be connected to an overflow
at the gas analyzer system's probe or to an overflow fitting between the probe and
transfer line to all the analyzers being verified. A setup that avoids pressure
pulsations due to stopping the flow through the gas blending device shall be used.
Any of these gas constituents if they are not relevant to the analyzers for this
verification shall be omitted. Alternatively the use of gas bottles with single gases
and a separate measurement of response times is allowed;

8.1.6. Response Time Verification for Compensation Type Analysers
8.1.6.1. Scope and Frequency
This verification shall be performed to determine a continuous gas analyzer's response,
where one analyzer's response is compensated by another's to quantify a gaseous
emission. For this check water vapour shall be considered to be a gaseous constituent.
This verification is required for continuous gas analyzers used for transient or rampedmodal
testing. This verification is not needed for batch gas analyzers or for continuous
gas analyzers that are used only for discrete-mode testing. This verification does not
apply to correction for water removed from the sample done in post-processing and it
does not apply to NMHC determination from THC and CH quoted in Annexes A.7. and
A.8. concerning the emission calculations. This verification shall be performed after
initial installation (i.e. test cell commissioning). After major maintenance,
Paragraph 8.1.5. may be used to verify uniform response provided that any replaced
components have gone through a humidified uniform response verification at some point.
8.1.6.2. Measurement Principles
This procedure verifies the time-alignment and uniform response of continuously
combined gas measurements. For this procedure, it is necessary to ensure that all
compensation algorithms and humidity corrections are turned on.
8.1.6.3. System Requirements
The general response time and rise time requirement given in 8.1.5.3 (a) is also valid for
compensation type analysers. Additionally, if the recording frequency is different
than the update frequency of the continuously combined/compensated signal, the
lower of these two frequencies shall be used for the verification required by
Paragraph 8.1.5.3(b)(i).
8.1.6.4. Procedure
All procedures given in Paragraph 8.1.5.4.(a) – (c) have to be used. Additionally also the
response and rise time of water vapour has to be measured, if a compensation algorithm
based on measured water vapour is used. In this case at least one of the used
calibration gases (but not NO ) has to be humidified as follows:
If the system does not use a sample dryer to remove water from the sample gas, the
span gas shall be humidified by flowing the gas mixture through a sealed vessel that
humidifies the gas to the highest sample dew point that is estimated during emission
sampling by bubbling it through distilled water. If the system uses a sample dryer during
testing that has passed the sample dryer verification check, the humidified gas mixture
may be introduced downstream of the sample dryer by bubbling it through distilled water
in a sealed vessel at (25 ± 10 °C), or a temperature greater than the dew point. In all
cases, downstream of the vessel, the humidified gas shall be maintained at a
temperature of at least 5 ºC above its local dew point in the line. Note that it is possible
to omit any of these gas constituents if they are not relevant to the analyzers for this
verification. If any of the gas constituents are not susceptible to water compensation, the
response check for these analyzers may be performed without humidification.

8.1.8. Flow-Related Measurements
8.1.8.1. Fuel Flow Calibration
Fuel flow meters shall be calibrated upon initial installation. The instrument
manufacturer's instructions shall be followed and good engineering judgment shall be
used to repeat the calibration.
8.1.8.2. Intake Air Flow Calibration
Intake air flow meters shall be calibrated upon initial installation. The instrument
manufacturer's instructions shall be followed and good engineering judgment shall be
used to repeat the calibration.
8.1.8.3. Exhaust Flow Calibration
Exhaust flow meters shall be calibrated upon initial installation. The instrument
manufacturer's instructions shall be followed and good engineering judgment shall be
used to repeat the calibration.
8.1.8.4. Diluted Exhaust flow (CVS) calibration
8.1.8.4.1. Overview
(a)
(b)
(c)
(d)
(e)
This section describes how to calibrate flow meters for diluted exhaust
constant-volume sampling (CVS) systems;
This calibration shall be performed while the flow meter is installed in its
permanent position. This calibration shall be performed after any part of the
flow configuration upstream or downstream of the flow meter has been
changed that may affect the flow-meter calibration. This calibration shall be
performed upon initial CVS installation and whenever corrective action does
not resolve a failure to meet the diluted exhaust flow verification (i.e., propane
check) in Paragraph 8.1.8.5;
A CVS flow meter shall be calibrated using a reference flow meter such as a
subsonic venturi flow meter, a long-radius flow nozzle, a smooth approach
orifice, a laminar flow element, a set of critical flow venturis, or an ultrasonic
flow meter. A reference flow meter shall be used that reports quantities that
are internationally-traceable within ±1% uncertainty. This reference flow
meter's response to flow shall be used as the reference value for CVS
flowmeter calibration;
An upstream screen or other restriction that could affect the flow ahead of the
reference flow meter may not be used, unless the flow meter has been
calibrated with such a restriction;
The calibration sequence described under this Paragraph 8.1.8.4. refers to the
molar based approach. For the corresponding sequence used in the mass
based approach, see Annex 8 Appendix 1.

(l)
(m)
The calibration shall be verified by performing a CVS verification (i.e., propane
check) as described in Paragraph 8.1.8.5;
The PDP may not be used below the lowest inlet pressure tested during
calibration.
8.1.8.4.3. CFV calibration
A critical-flow venturi (CFV) shall be calibrated to verify its discharge coefficient, C , at
the lowest expected static differential pressure between the CFV inlet and outlet. A
CFV flow meter shall be calibrated as follows:
(a) The system shall be connected as shown in Figure 8.1;
(b)
(c)
The blower shall be started downstream of the CFV;
While the CFV operates, a constant temperature at the CFV inlet shall be
maintained within ± 2% of the mean absolute inlet temperature, T ;
(d) Leaks between the calibration flow meter and the CFV shall be less than 0.3%
of the total flow at the highest restriction;
(e)
(f)
The variable restrictor shall be set to its wide-open position. In lieu of a variable
restrictor the pressure downstream of the CFV may be varied by varying blower
speed or by introducing a controlled leak. Note that some blowers have
limitations on non-loaded conditions;
The CFV shall be operated for at least 3 min to stabilize the system. The CFV
shall continue operating and the mean values of at least 30 s of sampled data
of each of the following quantities shall be recorded:
(i) The mean flow rate of the reference flow meter, q ;
(ii) Optionally, the mean dew point of the calibration air, T . See Annexes
A.7-A.8 for permissible assumptions during emission measurements;
(iii) The mean temperature at the venturi inlet, T ;
(iv) The mean static absolute pressure at the venturi inlet, p ;
(v)
The mean static differential pressure between the CFV inlet and the CFV
outlet, Δp ;
(g)
(h)
The restrictor valve shall be incrementally closed to decrease the absolute
pressure at the inlet to the CFV, p ;
The steps in Paragraphs (f) and (g) of this paragraph shall be repeated to
record mean data at a minimum of ten restrictor positions, such that the fullest
practical range of Δp expected during testing is tested. It is not required to
remove calibration components or CVS components to calibrate at the lowest
possible restrictions;

(iii) The mean temperature at the venturi inlet, T ;
(iv) The mean static absolute pressure at the venturi inlet, p ;
(v)
Static differential pressure between the static pressure at the venturi inlet
and the static pressure at the venturi throat, Δp ;
(g)
(h)
(i)
(j)
(k)
(l)
The restrictor valve shall be incrementally closed or the blower speed
decreased to decrease the flow rate;
The steps in Paragraphs (f) and (g) of this paragraph shall be repeated to
record data at a minimum of ten flow rates;
A functional form of C versus Re shall be determined by using the collected
data and the equations in Annexes A.7-A.8;
The calibration shall be verified by performing a CVS verification (i.e., propane
check) as described in Paragraph 8.1.8.5 using the new C versus Re
equation;
The SSV shall be used only between the minimum and maximum calibrated
flow rates;
The equations in Annex A.7 (molar based approach) or Annex A.8 (mass
based approach) shall be used to determine SSV flow during a test.
8.1.8.4.5. Ultrasonic calibration (reserved)

8.1.8.5. CVS and Batch Sampler Verification (Propane Check)
8.1.8.5.1. Introduction
(a)
A propane check serves as a CVS verification to determine if there is a
discrepancy in measured values of diluted exhaust flow. A propane check also
serves as a batch-sampler verification to determine if there is a discrepancy in
a batch sampling system that extracts a sample from a CVS, as described in
Paragraph (f) of this paragraph. Using good engineering judgment and safe
practices, this check may be performed using a gas other than propane, such
as CO or CO. A failed propane check might indicate one or more problems
that may require corrective action, as follows:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Incorrect analyzer calibration. The FID analyzer shall be re-calibrated,
repaired, or replaced;
Leak checks shall be performed on CVS tunnel, connections, fasteners,
and HC sampling system according to Paragraph 8.1.8.7;
The verification for poor mixing shall be performed in accordance with
Paragraph 9.2.2;
The hydrocarbon contamination verification in the sample system shall
be performed as described in Paragraph 7.3.1.2;
Change in CVS calibration. An in-situ calibration of the CVS flow meter
shall be performed as described in Paragraph 8.1.8.4;
Other problems with the CVS or sampling verification hardware or
software. The CVS system, CVS verification hardware, and software
shall be inspected for discrepancies;
(b)
A propane check uses either a reference mass or a reference flow rate of C H
as a tracer gas in a CVS. If a reference flow rate is used, any non-ideal gas
behaviour of C H in the reference flow meter shall be accounted for. See
Annexes A.7. (molar based approach) or A.8. (mass based approach), which
describe how to calibrate and use certain flow meters. No ideal gas
assumption may be used in Paragraph 8.1.8.5. and Annexes A.7. or A.8. The
propane check compares the calculated mass of injected C H using HC
measurements and CVS flow rate measurements with the reference value.

8.1.8.5.4. Preparation of the HC sampling system for the propane check
Vacuum side leak check verification of the HC sampling system may be performed
according to (g) of this paragraph. If this procedure is used, the HC contamination
procedure in Paragraph 7.3.1.2. may be used. If the vacuum side leak check is not
performed according to (g), then the HC sampling system shall be zeroed, spanned,
and verified for contamination, as follows:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
The lowest HC analyzer range that can measure the C H concentration
expected for the CVS and C H flow rates shall be selected;
The HC analyzer shall be zeroed using zero air introduced at the analyzer port;
The HC analyzer shall be spanned using C H span gas introduced at the
analyzer port;
Zero air shall be overflowed at the HC probe or into a fitting between the HC
probe and the transfer line;
The stable HC concentration of the HC sampling system shall be measured as
overflow zero air flows. For batch HC measurement, the batch container
(such as a bag) shall be filled and the HC overflow concentration measured;
If the overflow HC concentration exceeds 2 μmol/mol, the procedure may not
be advanced until contamination is eliminated. The source of the
contamination shall be determined and corrective action taken, such as
cleaning the system or replacing contaminated portions;
When the overflow HC concentration does not exceed 2 μmol/mol, this value
shall be recorded as x and it shall be used to correct for HC contamination
as described in Annex A.7. (molar based approach) or Annex A.8. (mass based
approach).
8.1.8.5.5. Propane check performance
(a)
The propane check shall be performed as follows:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
For batch HC sampling, clean storage media, such as evacuated bags
shall be connected;
HC measurement instruments shall be operated according to the
instrument manufacturer's instructions;
If correction for dilution air background concentrations of HC is foreseen,
background HC in the dilution air shall be measured and recorded;
Any integrating devices shall be zeroed;
Sampling shall begin and any flow integrators shall be started;
C H shall be released at the rate selected. If a reference flow rate of
C H is used, the integration of this flow rate shall be started;

(d)
(e)
If a reference mass (gravimetric technique) is used, the cylinder's propane
mass shall be determined within ± 0.5% and the C H reference mass shall be
determined by subtracting the empty cylinder propane mass from the full
cylinder propane mass. If a critical flow orifice (metering with a critical flow
orifice) is used, the propane mass shall be determined as flow rate multiplied
by the test time;
The reference C H mass shall be subtracted from the calculated mass. If this
difference is within ± 3.0% of the reference mass, the CVS passes this
verification.
8.1.8.5.7. PM secondary dilution system verification
When the propane check is to be repeated to verify the PM secondary dilution
system, the following procedure from (a) to (d) shall be used for this verification:
(a)
(b)
(c)
(d)
The HC sampling system shall be configured to extract a sample near the
location of the batch sampler's storage media (such as a PM filter). If the
absolute pressure at this location is too low to extract an HC sample, HC may
be sampled from the batch sampler pump's exhaust. Caution shall be used
when sampling from pump exhaust because an otherwise acceptable pump
leak downstream of a batch sampler flow meter will cause a false failure of the
propane check;
The propane check shall be repeated as described in this paragraph, but HC
shall be sampled from the batch sampler;
C H mass shall be calculated, taking into account any secondary dilution from
the batch sampler;
The reference C H mass shall be subtracted from the calculated mass. If this
difference is within ± 5% of the reference mass, the batch sampler passes this
verification. If not, corrective action shall be taken.
8.1.8.5.8. Sample dryer verification
If a humidity sensor for continuous monitoring of dew point at the sample dryer outlet
is used this check does not apply, as long as it is ensured that the dryer outlet
humidity is below the minimum values used for quench, interference, and
compensation checks.
(a)
(b)
If a sample dryer is used as allowed in Paragraph 9.3.2.3.1. to remove water
from the sample gas, the performance shall be verified upon installation, after
major maintenance, for thermal chiller. For osmotic membrane dryers, the
performance shall be verified upon installation, after major maintenance, and
within 35 days of testing;
Water can inhibit an analyzer's ability to properly measure the exhaust
component of interest and thus is sometimes removed before the sample gas
reaches the analyzer. For example water can negatively interfere with a CLD's
NO response through collisional quenching and can positively interfere with an
NDIR analyzer by causing a response similar to CO;

In this case, the maximum error of the difference shall be such that the accuracy of
q is within ± 5% when the dilution ratio is less than 15. It can be calculated by
taking root-mean-square of the errors of each instrument.
Acceptable accuracies of q can be obtained by either of the following methods:
(a)
The absolute accuracies of qmdew and qmdw are ± 0.2% which guarantees an
accuracy of q of ≤ 5% at a dilution ratio of 15. However, greater errors will
occur at higher dilution ratios;
(b) Calibration of q relative to qmdew is carried out such that the same
accuracies for qmp as in (a) are obtained. For details see Paragraph 8.1.8.6.2;
(c) The accuracy of q is determined indirectly from the accuracy of the dilution
ratio as determined by a tracer gas, e.g. CO . Accuracies equivalent to method
(a) for q are required;
(d)
The absolute accuracy of qmdew and qmdw is within ± 2% of full scale, the
maximum error of the difference between q and q is within 0.2% and the
linearity error is within ± 0.2% of the highest q observed during the test.
8.1.8.6.2. Calibration of differential flow measurement
The partial flow dilution system to extract a proportional raw exhaust sample shall be
periodically calibrated with an accurate flow meter traceable to international and/or
national standards. The flow meter or the flow measurement instrumentation shall be
calibrated in one of the following procedures, such that the probe flow q into the
tunnel shall fulfil the accuracy requirements of Paragraph 8.1.8.6.1.
(a)
The flow meter for qmdw shall be connected in series to the flow meter for
q , the difference between the two flow meters shall be calibrated for at least
5 set-points with flow values equally spaced between the lowest q value
used during the test and the value of q used during the test. The dilution
tunnel may be bypassed;
(b) A calibrated flow device shall be connected in series to the flowmeter for q
and the accuracy shall be checked for the value used for the test. The
calibrated flow device shall be connected in series to the flow meter for q ,
and the accuracy shall be checked for at least 5 settings corresponding to
dilution ratio between 3 and 15, relative to q used during the test;
(c)
The transfer line TL (see Figure 9.2) shall be disconnected from the exhaust
and a calibrated flow measuring device with a suitable range to measure q
shall be connected to the transfer line. qmdew shall be set to the value used
during the test, and qmdw shall be sequentially set to at least 5 values
corresponding to dilution ratios between 3 and 15. Alternatively, a special
calibration flow path may be provided, in which the tunnel is bypassed, but the
total and dilution air flow is passed through the corresponding meters as in the
actual test;

8.1.8.6.3.2. Determination of the transformation time
The system settings for the transformation time evaluation shall be the same as
during measurement of the test run. The transformation time, defined in Figure 3.1,
shall be determined by the following method:
An independent reference flowmeter with a measurement range appropriate for the
probe flow shall be put in series with and closely coupled to the probe. This
flowmeter shall have a transformation time of less than 100 ms for the flow step size
used in the response time measurement, with flow restriction sufficiently low as to not
affect the dynamic performance of the partial flow dilution system according to good
engineering judgment. A step change shall be introduced to the exhaust flow (or air
flow if exhaust flow is calculated) input of the partial flow dilution system, from a low
flow to at least 90% of full scale. The trigger for the step change shall be the same
one used to start the look-ahead control in actual testing. The exhaust flow step
stimulus and the flowmeter response shall be recorded at a sample rate of at least
10 Hz.
From this data, the transformation time shall be determined for the partial flow dilution
system, which is the time from the initiation of the step stimulus to the 50% point of
the flowmeter response. In a similar manner, the transformation times of the q
signal (i.e. sample flow of exhaust gas into partial flow dilution system) and of the
q signal (i.e. the exhaust gas mass flow rate on wet basis supplied by the exhaust
flow meter) shall be determined. These signals are used in the regression checks
performed after each test (see Paragraph 8.2.1.2.).
The calculation shall be repeated for at least 5 rise and fall stimuli, and the results
shall be averaged. The internal transformation time (<100 ms) of the reference
flowmeter shall be subtracted from this value. In the case that the system in
accordance with Paragraph 8.2.1.2. requires the "look-ahead" method, this is the
"look-ahead" value of the partial flow dilution system to be applied in accordance with
Paragraph 8.2.1.2.
8.1.8.7. Vacuum-Side Leak Verification
8.1.8.7.1. Scope and frequency
Upon initial sampling system installation, after major maintenance such as pre-filter
changes, and within 8 hours prior to each duty-cycle sequence, it shall be verified that
there are no significant vacuum-side leaks using one of the leak tests described in
this section. This verification does not apply to any full-flow portion of a CVS dilution
system.
8.1.8.7.2. Measurement principles
A leak may be detected either by measuring a small amount of flow when there shall
be zero flow, by detecting the dilution of a known concentration of span gas when it
flows through the vacuum side of a sampling system or by measuring the pressure
increase of an evacuated system.

8.1.8.7.5. Vacuum-decay leak test
To perform this test a vacuum shall be applied to the vacuum-side volume of the
sampling system and the leak rate of the system shall be observed as a decay in the
applied vacuum. To perform this test the vacuum-side volume of the sampling
system shall be known to within ± 10% of its true volume. For this test measurement
instruments that meet the specifications of Paragraphs 8.1. and 9.4. shall also be
used.
A vacuum-decay leak test shall be performed as follows:
(a)
The probe end of the system shall be sealed as close to the probe opening as
possible by taking one of the following steps:
(i)
(ii)
(iii)
The end of the sample probe shall be capped or plugged;
The transfer line at the probe shall be disconnected and the transfer line
capped or plugged;
A leak-tight valve in-line between a probe and transfer line shall be
closed;
(b)
(c)
All vacuum pumps shall be operated. A vacuum shall be drawn that is
representative of normal operating conditions. In the case of sample bags, it is
recommend that the normal sample bag pump-down procedure be repeated
twice to minimize any trapped volumes;
The sample pumps shall be turned off and the system sealed. The absolute
pressure of the trapped gas and optionally the system absolute temperature
shall be measured and recorded. Sufficient time shall be allowed for any
transients to settle and long enough for a leak at 0.5% to have caused a
pressure change of at least 10 times the resolution of the pressure transducer.
The pressure and optionally temperature shall be recorded once again;

8.1.9.1.3. System requirements
8.1.9.1.4. Procedure
A CO NDIR analyzer shall have an H O interference that is within (0.0 ± 0.4)
mmol/mol (of the expected mean CO concentration).
The interference verification shall be performed as follows:
(a)
(b)
(c)
(d)
The CO NDIR analyzer shall be started, operated, zeroed, and spanned as it
would be before an emission test;
A humidified test gas shall be created by bubbling zero air that meets the
specifications in Paragraph 9.5.1 through distilled water in a sealed vessel. If
the sample is not passed through a dryer, control the vessel temperature to
generate an H O level at least as high as the maximum expected during
testing. If the sample is passed through a dryer during testing, control the
vessel temperature to generate an H O level at least as high as the level
determined in Paragraph 9.3.2.3.1;
The humidified test gas temperature shall be maintained at least 5 °C above its
dew point downstream of the vessel;
The humidified test gas shall be introduced into the sampling system. The
humidified test gas may be introduced downstream of any sample dryer, if one
is used during testing;
(e) The water mole fraction, x , of the humidified test gas shall be measured, as
close as possible to the inlet of the analyzer. For example, dew point, T ,
and absolute pressure p , shall be measured to calculate x ;
(f)
(g)
(h)
Good engineering judgment shall be used to prevent condensation in the
transfer lines, fittings, or valves from the point where x is measured to the
analyzer;
Time shall be allowed for the analyzer response to stabilize. Stabilization time
shall include time to purge the transfer line and to account for analyzer
response;
While the analyzer measures the sample's concentration, 30 s of sampled data
shall be recorded. The arithmetic mean of this data shall be calculated. The
analyzer meets the interference verification if this value is within (0.0 ± 0.4)
mmol/mol
8.1.9.2. H O and CO Interference Verification for CO NDIR Analyzers
8.1.9.2.1. Scope and frequency
If CO is measured using an NDIR analyzer, the amount of H O and CO interference
shall be verified after initial analyzer installation and after major maintenance.

(i)
Interference procedures for CO and H O may be also run separately. If the
CO and H O levels used are higher than the maximum levels expected during
testing, each observed interference value shall be scaled down by multiplying
the observed interference by the ratio of the maximum expected concentration
value to the actual value used during this procedure. Separate interference
procedures concentrations of H O (down to 0.025 mol/mol H O content) that
are lower than the maximum levels expected during testing may be run, but the
observed H O interference shall be scaled up by multiplying the observed
interference by the ratio of the maximum expected H O concentration value to
the actual value used during this procedure. The sum of the two scaled
interference values shall meet the tolerance in Paragraph 8.1.9.2.3.
8.1.10. Hydrocarbon Measurements
8.1.10.1. FID optimization and Verification
8.1.10.1.1. Scope and frequency
For all FID analyzers, the FID shall be calibrated upon initial installation. The
calibration shall be repeated as needed using good engineering judgment. The
following steps shall be performed for a FID that measures HC:
(a)
(b)
(c)
A FID's response to various hydrocarbons shall be optimized after initial
analyzer installation and after major maintenance. FID response to propylene
and toluene shall be between 0.9 and 1.1 relative to propane;
A FID's methane (CH ) response factor shall be determined after initial
analyzer installation and after major maintenance as described in
Paragraph 8.1.10.1.4. of this section;
Methane (CH ) response shall be verified within 185 days before testing.
8.1.10.1.2. Calibration
Good engineering judgment shall be used to develop a calibration procedure, such as
one based on the FID-analyzer manufacturer's instructions and recommended
frequency for calibrating the FID. For a FID that measures HC, it shall be calibrated
using C H calibration gases that meet the specifications of Paragraph 9.5.1. For a
FID that measures CH , it shall be calibrated using CH calibration gases that meet
the specifications of Paragraph 9.5.1. Regardless of the calibration gas composition,
it shall be calibrated on a carbon number basis of one (C ).

8.1.10.1.4. HC FID CH response factor determination
This procedure is only for FID analyzers that measure HC. Since FID analyzers
generally have a different response to CH versus C H , each THC FID analyzer's
CH response factor, RF shall be determined, after FID optimization. The
most recent RF measured according to this paragraph shall be used in the
calculations for HC determination described in Annex A.7. (molar based approach) or
Annex A.8. (mass based approach) to compensate for CH response. RF
shall be determined as follows, noting that RF is not determined for FIDs
that are calibrated and spanned using CH with a non-methane cutter:
(a)
(b)
(c)
A C H span gas concentration shall be selected to span the analyzer before
emission testing. Only span gases that meets the specifications of
Paragraph 9.5.1. shall be selected and the C H concentration of the gas shall
be recorded;
A CH span gas that meets the specifications of Paragraph 9.5.1. shall be
selected and the CH concentration of the gas shall be recorded,
The FID analyzer shall be operated according to the manufacturer's
instructions;
(d) It shall be confirmed that the FID analyzer has been calibrated using C H .
Calibration shall be performed on a carbon number basis of one (C );
(e)
(f)
(g)
(h)
(i)
(j)
The FID shall be zeroed with a zero gas used for emission testing;
The FID shall be spanned with the selected C H span gas;
The selected CH span gas shall be introduced at the sample port of the FID
analyzer, the CH span gas that has been selected under Paragraph (b) of this
paragraph;
The analyzer response shall be stabilized. Stabilization time may include time
to purge the analyzer and to account for its response;
While the analyzer measures the CH concentration, 30 s of sampled data shall
be recorded and the arithmetic mean of these values shall be calculated;
The mean measured concentration shall be divided by the recorded span
concentration of the CH calibration gas. The result is the FID analyzer's
response factor for CH , RF .

8.1.10.2.4. Procedure
FID O interference shall be determined as follows, noting that one or more gas
dividers may be used to create reference gas concentrations that are required to
perform this verification:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
Three span reference gases shall be selected that meet the specifications in
Paragraph 9.5.1. and contain C H concentration used to span the analyzers
before emissions testing. Only span gases that meet the specifications in
Paragraph 9.5.1. CH span reference gases may be used for FIDs calibrated
on CH with a non-methane cutter. The three balance gas concentrations shall
be selected such that the concentrations of O and N represent the minimum
and maximum and intermediate O concentrations expected during testing.
The requirement for using the average O concentration can be removed if the
FID is calibrated with span gas balanced with the average expected oxygen
concentration;
It shall be confirmed that the FID analyzer meets all the specifications of
Paragraph 8.1.10.1;
The FID analyzer shall be started and operated as it would be before an
emission test. Regardless of the FID burner's air source during testing, zero air
shall be used as the FID burner's air source for this verification;
The analyzer shall be set at zero;
The analyzer shall be spanned using a span gas that is used during emissions
testing;
The zero response shall be checked by using the zero gas used during
emission testing. It shall be proceeded to the next step if the mean zero
response of 30 s of sampled data is within ± 0.5% of the span reference value
used in Paragraph (e) of this paragraph, otherwise the procedure shall be
restarted at Paragraph (d) of this paragraph;
The analyzer response shall be checked using the span gas that has the
minimum concentration of O expected during testing. The mean response of
30 s of stabilized sample data shall be recorded as x ;
The zero response of the FID analyzer shall be checked using the zero gas
used during emission testing. The next step shall be performed if the mean
zero response of 30 s of stabilized sample data is within ± 0.5% of the span
reference value used in Paragraph (e) of this paragraph, otherwise the
procedure shall be restarted at Paragraph (d) of this paragraph;
The analyzer response shall be checked using the span gas that has the
average concentration of O expected during testing. The mean response of
30 s of stabilized sample data shall be recorded as x ;

8.1.10.3. Non-Methane Cutter Penetration Fractions
8.1.10.3.1. Scope and frequency
If a FID analyzer and a non-methane cutter (NMC) is used to measure methane
(CH ), the non-methane cutter's conversion efficiencies of methane, E , and
ethane, E shall be determined. As detailed in this paragraph, these conversion
efficiencies may be determined as a combination of NMC conversion efficiencies and
FID analyzer response factors, depending on the particular NMC and FID analyzer
configuration.
This verification shall be performed after installing the non-methane cutter. This
verification shall be repeated within 185 days of testing to verify that the catalytic
activity of the cutter has not deteriorated.
8.1.10.3.2. Measurement principles
A non-methane cutter is a heated catalyst that removes non-methane hydrocarbons
from the exhaust stream before the FID analyzer measures the remaining
hydrocarbon concentration. An ideal non-methane cutter would have a methane
conversion efficiency E [-] of 0 (that is, a methane penetration fraction, PF , of
1.000), and the conversion efficiency for all other hydrocarbons would be 1.000, as
represented by an ethane conversion efficiency E [-] of 1 (that is, an ethane
penetration fraction PF [-] of 0). The emission calculations in Annex A.7. or
Annex A.8. use this paragraph's measured values of conversion efficiencies E and
E to account for less than ideal NMC performance.
8.1.10.3.3. System requirements
8.1.10.3.4. Procedure
NMC conversion efficiencies are not limited to a certain range. However, it is
recommended that a non-methane cutter is optimized by adjusting its temperature to
achieve a E < 0.15 and a E > 0.98 (PF > 0.85 and PF < 0.02) as
determined by Paragraph 8.1.10.3.4., as applicable. If adjusting NMC temperature
does not result in achieving these specifications, it is recommended that the catalyst
material is replaced. The most recently determined conversion values from this
section shall be used to calculate HC emissions according to Annexes A.7-A.8 as
applicable.
Any one of the procedures specified in Paragraphs 8.1.10.3.4.1., 8.1.10.3.4.2. and
8.1.10.3.4.3. is recommended. An alternative method recommended by the
instrument manufacturer may be used.

8.1.10.3.4.2. Procedure for a FID calibrated with propane bypassing the NMC
If a FID is used with an NMC that is calibrated with propane, C H , by bypassing the
NMC, penetrations fractions PF
and PF
shall be determined as
follows:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
A CH gas mixture and a C H analytical gas mixture shall be selected meeting
the specifications of Paragraph 9.5.1 with the CH concentration typical of its
peak concentration expected at the hydrocarbon standard and the C H
concentration typical of the peak total hydrocarbon (THC) concentration
expected at the hydrocarbon standard or the THC analyzer span value;
The non-methane cutter shall be started and operated according to the
manufacturer's instructions, including any temperature optimization;
It shall be confirmed that the FID analyzer meets all the specifications of
Paragraph 8.1.10.1;
The FID analyzer shall be operated according to the manufacturer's
instructions;
The FID shall be zeroed and spanned as it would be during emission testing.
The FID shall be spanned by bypassing the cutter and by using C H span gas
to span the FID. The FID shall be spanned on a C basis;
The C H analytical gas mixture shall be introduced upstream of the
non-methane cutter at the same point the zero gas was introduced;
Time shall be allowed for the analyzer response to stabilize. Stabilization time
may include time to purge the non-methane cutter and to account for the
analyzer's response;
While the analyzer measures a stable concentration, 30 s of sampled data shall
be recorded and the arithmetic mean of these data points shall be calculated;
The flow path shall be rerouted to bypass the non-methane cutter, the C H
analytical gas mixture shall be introduced to the bypass, and the steps in
Paragraphs (g) through (h) of this paragraph shall be repeated;
The mean C H concentration measured through the non-methane cutter shall
be divided by the mean concentration measured after bypassing the
non-methane cutter. The result is the C H penetration fraction, PF ,
that is equivalent to (1- E [-]). This penetration fraction shall be used
according to A.7. or A.8., as applicable;
The steps in Paragraphs (f) through (j) of this paragraph shall be repeated, but
with the CH analytical gas mixture instead of C H . The result will be the CH
penetration fraction, PF (equivalent to (1- E [-])). This penetration
fraction shall be used according to Annexes A.7-A.8, as applicable.

8.1.11. NO measurements
8.1.11.1. CLD CO and H O Quench Verification
8.1.11.1.1. Scope and frequency
If a CLD analyzer is used to measure NO , the amount of H O and CO quench shall
be verified after installing the CLD analyzer and after major maintenance.
8.1.11.1.2. Measurement principles
H O and CO can negatively interfere with a CLD's NO response by collisional
quenching, which inhibits the chemiluminescent reaction that a CLD utilizes to detect
NO . This procedure and the calculations in Paragraph 8.1.11.2.3. determine quench
and scale the quench results to the maximum mole fraction of H O and the maximum
CO concentration expected during emission testing. If the CLD analyzer uses
quench compensation algorithms that utilize H O and/or CO measurement
instruments, quench shall be evaluated with these instruments active and with the
compensation algorithms applied.
8.1.11.1.3. System requirements
For dilute measurement a CLD analyzer shall not exceed a combined H O and CO
quench of ± 2%. For raw measurement a CLD analyzer shall not exceed a combined
H O and CO quench of ± 2%. Combined quench is the sum of the CO quench
determined as described in Paragraph 8.1.11.1.4. and the H O quench as determined
in Paragraph 8.1.11.1.5. If these requirements are not met, corrective action shall be
taken by repairing or replacing the analyzer. Before running emission tests, it shall be
verified that the corrective action have successfully restored the analyzer to proper
functioning.
8.1.11.1.4. CO quench verification procedure
The following method or the method prescribed by the instrument manufacturer may
be used to determine CO quench by using a gas divider that blends binary span
gases with zero gas as the diluent and meets the specifications in Paragraph 9.4.5.6.,
or good engineering judgment shall be used to develop a different protocol:
(a)
(b)
(c)
(d)
PTFE or stainless steel tubing shall be used to make necessary connections;
The gas divider shall be configured such that nearly equal amounts of the span
and diluent gases are blended with each other;
If the CLD analyzer has an operating mode in which it detects NO-only, as
opposed to total NO , the CLD analyzer shall be operated in the NO-only
operating mode;
A CO span gas that meets the specifications of Paragraph 9.5.1. and a
concentration that is approximately twice the maximum CO concentration
expected during emission testing shall be used;

8.1.11.1.5. H O quench verification procedure
The following method or the method prescribed by the instrument manufacturer may
be used to determine H O quench, or good engineering judgment shall be used to
develop a different protocol:
(a)
(b)
PTFE or stainless steel tubing shall be used to make necessary connections;
If the CLD analyzer has an operating mode in which it detects NO-only, as
opposed to total NO , the CLD analyzer shall be operated in the NO-only
operating mode;
(c) A NO span gas shall be used that meets the specifications of Paragraph 9.5.1.
and a concentration that is near the maximum concentration expected during
emission testing. Higher concentration may be used according to the
instrument manufacturer's recommendation and good engineering judgement
in order to obtain accurate verification, if the expected NO concentration is
lower than the minimum range for the verification specified by the instrument
manufacturer;
(d)
(e)
(f)
(g)
The CLD analyzer shall be zeroed and spanned. The CLD analyzer shall be
spanned with the NO span gas from Paragraph (c) of this paragraph, the span
gas concentration shall be recorded as x , and it shall be used in the
quench verification calculations in Paragraph 8.1.11.2.3;
The NO span gas shall be humidified by bubbling it through distilled water in a
sealed vessel. If the humidified NO span gas sample does not pass through a
sample dryer for this verification test, the vessel temperature shall be controlled
to generate an H O level approximately equal to the maximum mole fraction of
H O expected during emission testing. If the humidified NO span gas sample
does not pass through a sample dryer, the quench verification calculations in
Paragraph 8.1.11.2.3. scale the measured H O quench to the highest mole
fraction of H O expected during emission testing. If the humidified NO span
gas sample passes through a dryer for this verification test, the vessel
temperature shall be controlled to generate an H O level at least as high as the
level determined in Paragraph 9.3.2.3.1. For this case, the quench verification
calculations in Paragraph 8.1.11.2.3. do not scale the measured H O quench;
The humidified NO test gas shall be introduced into the sample system. It may
be introduced upstream or downstream of a sample dryer that is used during
emission testing. Depending on the point of introduction, the respective
calculation method of Paragraph (e) shall be selected. Note that the sample
dryer shall meet the sample dryer verification check in Paragraph 8.1.8.5.8;
The mole fraction of H O in the humidified NO span gas shall be measured. In
case a sample dryer is used, the mole fraction of H O in the humidified NO
span gas shall be measured downstream of the sample dryer, x . It is
recommended to measure x as close as possible to the CLD analyzer
inlet. x may be calculated from measurements of dew point, T , and
absolute pressure, p ;

8.1.11.2.3. Combined H O and CO quench calculations Combined H O and CO quench shall
be calculated as follows:
⎡⎛
X


⎢⎜

1

⎢⎜
− X
1
⎟ X ⎛ X ⎞ X
quench =
⋅ +
⋅ ⎥ ⋅ 100%






(8-4)
X
X ⎝ X ⎠ X ⎥
⎢⎜


⎣⎝


Where:
quench = amount of CLD quench
x
=
measured concentration of NO upstream of a bubbler, according to
Paragraph 8.1.11.1.5.(d)
x
=
measured concentration of NO downstream of a bubbler, according
to Paragraph 8.1.11.1.5.(i)
x
=
maximum expected mole fraction of water during emission testing
according to Paragraph 8.1.11.2.1.
x
=
measured mole fraction of water during the quench verification
according to Paragraph 8.1.11.1.5.(g)
x
=
measured concentration of NO when NO span gas is blended with
CO span gas, according to Paragraph 8.1.11.1.4.(j)
x
=
actual concentration of NO when NO span gas is blended with CO
span gas, according to Paragraph 8.1.11.1.4.(k) and calculated
according to equation (8-5)
x
=
maximum expected concentration of CO during emission testing,
according to Paragraph 8.1.11.2.2.
x
=
actual concentration of CO when NO span gas is blended with CO
span gas, according to Paragraph 8.1.11.1.4.(i)
X
⎛ X ⎞
= ⎜1 − ⎟ ⋅ X
X
(8-5)


Where:
x
=
the NO span gas concentration input to the gas divider, according to
Paragraph 8.1.11.1.4.(e)
x
=
the CO span gas concentration input to the gas divider, according
to Paragraph 8.1.11.1.4.(d)

(g)
This difference shall be multiplied by the ratio of the expected mean HC
concentration to the HC concentration measured during the verification. The
analyzer meets the interference verification of this paragraph if this result is
within ± 2% of the NO concentration expected at the standard:
⎛ X ⎞
( X
X
) ⋅ ⎜ ⎟ ≤ 2%
⋅ ( X )
Where:
− (8-6)
⎜ X ⎟
⎝ ⎠
X = the mean concentration of NO measured by CLD
[μmol/mol] or [ppm]
( X ) = the mean concentration of NO measured by NDUV
[μmol/mol] or [ppm]
X = the mean concentration of HC measured [μmol/mol] or
[ppm]
X = the mean concentration of HC expected at the standard
[μmol/mol] or [ppm]
X = the mean concentration of NO expected at the standard
[μmol/mol] or [ppm]
8.1.11.3.5. Cooling bath (chiller) requirements
It shall be demonstrated that for the highest expected water vapour concentration H ,
the water removal technique maintains CLD humidity at ≤ 5 g water/kg dry air
(or about 0.8 volume% H O), which is 100% relative humidity at 3.9 °C and
101.3 kPa. This humidity specification is also equivalent to about 25% relative
humidity at 25 °C and 101.3 kPa. This may be demonstrated by measuring the
temperature at the outlet of a thermal dehumidifier, or by measuring humidity at a
point just upstream of the CLD.
8.1.11.4. Cooling bath (chiller) NO penetration
8.1.11.4.1. Scope and frequency
If a cooling bath (chiller) is used to dry a sample upstream of a NO measurement
instrument, but no NO -to-NO converter is used upstream of the cooling bath, this
verification shall be performed for cooling bath NO penetration. This verification
shall be performed after initial installation and after major maintenance.

(vii)
It shall be immediately switched back to overflowing the NO calibration
gas used to establish x . It shall be allowed for stabilization of the
total NO response, accounting only for transport delays and instrument
response. The mean of 30 s of recorded total NO data shall be
calculated and this value recorded as x ;
(viii) x shall be corrected to x based upon the residual water
vapour that passed through the chiller at the chiller's outlet temperature
and pressure;
(c)
Performance evaluation. If x
is less than 95% of x
, the chiller shall be
repaired or replaced.
8.1.11.5. NO -to-NO Converter Conversion Verification
8.1.11.5.1. Scope and frequency
If an analyzer is used that measures only NO to determine NO , an NO -to-NO
converter shall be used upstream of the analyzer. This verification shall be performed
after installing the converter, after major maintenance and within 35 days before an
emission test. This verification shall be repeated at this frequency to verify that the
catalytic activity of the NO -to-NO converter has not deteriorated.
8.1.11.5.2. Measurement principles
An NO -to-NO converter allows an analyzer that measures only NO to determine total
NO by converting the NO in exhaust to NO.
8.1.11.5.3. System requirements
8.1.11.5.4 Procedure
An NO -to-NO converter shall allow for measuring at least 95% of the total NO at the
maximum expected concentration of NO .
The following procedure shall be used to verify the performance of a NO -to-NO
converter:
(a)
(b)
For the instrument setup the analyzer and NO -to-NO converter manufacturers'
start-up and operating instructions shall be followed. The analyzer and
converter shall be adjusted as needed to optimize performance;
An ozonator's inlet shall be connected to a zero-air or oxygen source and its
outlet shall be connected to one port of a 3-way tee fitting. An NO span gas
shall be connected to another port and the NO -to-NO converter inlet shall be
connected to the last port;

(d)
Performance evaluation. The efficiency of the NO converter shall be
calculated by substituting the concentrations obtained into the following
equation:
⎛ X − X ⎞
Efficiency [%] =
⎜1
+
⎟ × 100
(8-7)
⎝ X − X ⎠
(e)
If the result is less than 95%, the NO -to-NO converter shall be repaired or
replaced.
8.1.12. PM Measurements
8.1.12.1. PM Balance Verifications and Weighing Process Verification
8.1.12.1.1. Scope and frequency
This paragraph describes three verifications.
(a)
(b)
(c)
Independent verification of PM balance performance within 370 days prior to
weighing any filter;
Zero and span of the balance within 12 h prior to weighing any filter;
Verification that the mass determination of reference filters before and after a
filter weighing session be less than a specified tolerance.
8.1.12.1.2. Independent verification
The balance manufacturer (or a representative approved by the balance
manufacturer) shall verify the balance performance within 370 days of testing in
accordance with internal audit procedures.
8.1.12.1.3. Zeroing and spanning
Balance performance shall be verified by zeroing and spanning it with at least one
calibration weight, and any weights that are used shall meet the specifications in
Paragraph 9.5.2. to perform this verification. A manual or automated procedure shall
be used:
(a)
(b)
A manual procedure requires that the balance shall be used in which the
balance shall be zeroed and spanned with at least one calibration weight. If
normally mean values are obtained by repeating the weighing process to
improve the accuracy and precision of PM measurements, the same process
shall be used to verify balance performance;
An automated procedure is carried out with internal calibration weights that are
used automatically to verify balance performance. These internal calibration
weights shall meet the specifications in Paragraph 9.5.2. to perform this
verification.

(i)
(j)
If any of the reference filters' observed mass changes by more than that
allowed under this paragraph, all PM mass determinations made since the last
successful reference media (e.g. filter) mass validation shall be invalidated.
Reference PM filters maybe discarded if only one of the filters mass has
changed by more than the allowable amount and a special cause for that filter's
mass change can be positively identified which would not have affected other
in-process filters. Thus the validation can be considered a success. In this
case, the contaminated reference media shall not be included when
determining compliance with Paragraph (j) of this paragraph, but the affected
reference filter shall be discarded and replaced;
If any of the reference masses change by more than that allowed under this
Paragraph 8.1.12.1.4., all PM results that were determined between the two
times that the reference masses were determined shall be invalidated. If
reference PM sample media is discarded according to Paragraph (i) of this
paragraph, at least one reference mass difference that meets the criteria in this
Paragraph 8.1.12.1.4. shall be available. Otherwise, all PM results that were
determined between the two times that the reference media (e.g. filters)
masses were determined shall be invalidated.
8.1.12.2. PM Sample Filter Buoyancy Correction
8.1.12.2.1. General
PM sample filter shall be corrected for their buoyancy in air. The buoyancy correction
depends on the sample media density, the density of air, and the density of the
calibration weight used to calibrate the balance. The buoyancy correction does not
account for the buoyancy of the PM itself, because the mass of PM typically accounts
for only (0.01 to 0.10)% of the total weight. A correction to this small fraction of mass
would be at the most 0.010%. The buoyancy-corrected values are the tare masses of
the PM samples. These buoyancy-corrected values of the pre-test filter weighing are
subsequently subtracted from the buoyancy-corrected values of the post-test
weighing of the corresponding filter to determine the mass of PM emitted during the
test
8.1.12.2.2. PM sample filter density
Different PM sample filter have different densities. The known density of the sample
media shall be used, or one of the densities for some common sampling media shall
be used, as follows:
(a)
(b)
(c)
For PTFE-coated borosilicate glass, a sample media density of 2300 kg/m
shall be used;
For PTFE membrane (film) media with an integral support ring of
polymethylpentene that accounts for 95% of the media mass, a sample media
density of 920 kg/m shall be used;
For PTFE membrane (film) media with an integral support ring of PTFE, a
sample media density of 2144 kg/m shall be used.

8.2. Instrument Validation for Test
8.2.1. Validation of Proportional Flow Control for Batch Sampling and Minimum Dilution
Ratio for PM Batch Sampling
8.2.1.1. Proportionality Criteria for CVS
8.2.1.1.1. Proportional flows
For any pair of flow meters, the recorded sample and total flow rates or their 1 Hz
means shall be used with the statistical calculations in Annex A.2.9. The standard
error of the estimate, SEE, of the sample flow rate versus the total flow rate shall be
determined. For each test interval, it shall be demonstrated that SEE was less than
or equal to 3.5% of the mean sample flow rate.
8.2.1.1.2. Constant flows
For any pair of flow meters, the recorded sample and total flow rates or their 1 Hz
means shall be used to demonstrate that each flow rate was constant within ± 2.5%
of its respective mean or target flow rate. The following options may be used instead
of recording the respective flow rate of each type of meter:
(a)
(b)
Critical-flow venturi option. For critical-flow venturis, the recorded venturi inlet
conditions or their 1 Hz means shall be used. It shall be demonstrated that the
flow density at the venturi inlet was constant within ± 2.5% of the mean or
target density over each test interval. For a CVS critical-flow venturi, this may
be demonstrated by showing that the absolute temperature at the venturi inlet
was constant within ± 4% of the mean or target absolute temperature over
each test interval;
Positive-displacement pump option. The recorded pump-inlet conditions or
their 1 Hz means shall be used. It shall be demonstrated that the flow density
at the pump inlet was constant within ± 2.5% of the mean or target density over
each test interval. For a CVS pump, this may be demonstrated by showing that
the absolute temperature at the pump inlet was constant within ± 2% of the
mean or target absolute temperature over each test interval.
8.2.1.1.3. Demonstration of proportional sampling
For any proportional batch sample such as a bag or PM filter, it shall be demonstrated
that proportional sampling was maintained using one of the following, noting that up
to 5% of the total number of data points may be omitted as outliers.
Using good engineering judgment, it shall be demonstrated with an engineering
analysis that the proportional-flow control system inherently ensures proportional
sampling under all circumstances expected during testing. For example, CFVs may
be used for both sample flow and total flow if it is demonstrated that they always have
the same inlet pressures and temperatures and that they always operate under
critical-flow conditions.
Measured or calculated flows and/or tracer gas concentrations (e.g. CO ) shall be
used to determine the minimum dilution ratio for PM batch sampling over the test
interval.

8.2.2.1.2. Continuous sampling
For continuous sampling, the entire test shall be repeated using the next higher
analyzer range. If the analyzer again operates above 100% of its range, the test shall
be repeated using the next higher range. The test shall be continued to be repeated
until the analyzer always operates at less than 100% of its range for the entire test.
8.2.2.2. Drift Validation and Drift Correction
If the drift is within ± 1%, the data can be either accepted without any correction or
accepted after correction. If the drift is greater than ± 1%, two sets of brake specific
emission results shall be calculated for each pollutant, or the test shall be voided.
One set shall be calculated using data before drift correction and another set of data
calculated after correcting all the data for drift according to Appendix 2 of Annexes
A.7. or A.8. The comparison shall be made as a percentage of the uncorrected
results. The difference between the uncorrected and the corrected brake-specific
emission values shall be within ± 4% of the uncorrected brake-specific emission
values. If not, the entire test is void.
8.2.3. PM Sampling Media (e.g. filters) Preconditioning and Tare Weighing
Before an emission test, the following steps shall be taken to prepare PM sample filter
media and equipment for PM measurements:
8.2.3.1. Periodic Verifications
It shall be made sure that the balance and PM-stabilization environments meet the
periodic verifications in Paragraph 8.1.12. The reference filter shall be weighed just
before weighing test filters to establish an appropriate reference point (see section
details of the procedure in Paragraph 8.1.12.1.). The verification of the stability of the
reference filters shall occur after the post-test stabilisation period, immediately before
the post-test weighing.
8.2.3.2. Visual Inspection
8.2.3.3. Grounding
The unused sample filter media shall be visually inspected for defects, defective filters
shall be discarded.
Electrically grounded tweezers or a grounding strap shall be used to handle PM filters
as described in Paragraph 9.3.4.
8.2.3.4. Unused Sample Media
Unused sample media shall be placed in one or more containers that are open to the
PM-stabilization environment. If filters are used, they may be placed in the bottom
half of a filter cassette.

8.2.3.10. Substitution Weighing
Substitution weighing is an option and, if used, involves measurement of a reference
weight before and after each weighing of a PM sampling medium (e.g. filter). While
substitution weighing requires more measurements, it corrects for a balance's
zero-drift and it relies on balance linearity only over a small range. This is most
appropriate when quantifying total PM masses that are less than 0.1% of the sample
medium's mass. However, it may not be appropriate when total PM masses
exceed 1% of the sample medium's mass. If substitution weighing is used, it shall be
used for both pre-test and post-test weighing. The same substitution weight shall be
used for both pre-test and post-test weighing. The mass of the substitution weight
shall be corrected for buoyancy if the density of the substitution weight is less than
2.0 g/cm . The following steps are an example of substitution weighing:
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
Electrically grounded tweezers or a grounding strap shall be used, as
described in Paragraph 9.3.4.6;
A static neutralizer shall be used as described in Paragraph 9.3.4.6 to minimize
static electric charge on any object before it is placed on the balance pan;
A substitution weight shall be selected that meets the specifications for
calibration weights in Paragraph 9.5.2. The substitution weight shall also have
the same density as the weight that is used to span the microbalance, and shall
be similar in mass to an unused sample medium (e.g. filter). If filters are used,
the weight's mass should be about (80 to 100) mg for typical 47 mm diameter
filters;
The stable balance reading shall be recorded and then the calibration weight
shall be removed;
An unused sampling medium (e.g. a new filter) shall be weighed, the stable
balance reading recorded and the balance environment's dew point, ambient
temperature, and atmospheric pressure recorded;
The calibration weight shall be reweighed and the stable balance reading
recorded;
The arithmetic mean of the two calibration-weight readings that were recorded
immediately before and after weighing the unused sample shall be calculated.
That mean value shall be subtracted from the unused sample reading, then the
true mass of the calibration weight as stated on the calibration-weight
certificate shall be added. This result shall be recorded. This is the unused
sample's tare weight without correcting for buoyancy;
These substitution-weighing steps shall be repeated for the remainder of the
unused sample media;
The instructions given in Paragraphs 8.2.3.7. through 8.2.3.9. of this section
shall be followed once weighing is completed.

8.2.4.6. Determination of Post-Test Filter Mass
8.2.4.7. Total Mass
The procedures in Paragraph 8.2.3. shall be repeated (Paragraphs 8.2.3.6. through
8.2.3.9.) to determine the post-test filter mass.
Each buoyancy-corrected filter tare mass shall be subtracted from its respective
buoyancy-corrected post-test filter mass. The result is the total mass, m , which
shall be used in emission calculations in Annexes A.7. and A.8.
9. MEASUREMENT EQUIPMENT
9.1. Engine Dynamometer Specification
9.1.1. Shaft Work
An engine dynamometer shall be used that has adequate characteristics to perform
the applicable duty cycle including the ability to meet appropriate cycle validation
criteria. The following dynamometers may be used:
(a)
(b)
(c)
Eddy-current or water-brake dynamometers;
Alternating-current or direct-current motoring dynamometers;
One or more dynamometers.
9.1.2. Transient Cycle
Load cell or in-line torque meter may be used for torque measurements.
When using a load cell, the torque signal shall be transferred to the engine axis and
the inertia of the dynamometer shall be considered. The actual engine torque is the
torque read on the load cell plus the moment of inertia of the brake multiplied by the
angular acceleration. The control system has to perform such a calculation in real
time.
9.1.3. Engine Accessories
The work of engine accessories required to fuel, lubricate, or heat the engine,
circulate liquid coolant to the engine, or to operate after-treatment devices shall be
accounted for and they shall be installed in accordance with Paragraph 6.3.

(b)
(c)
(d)
The exhaust system backpressure shall not be artificially lowered by the
dilution air inlet system. The static pressure at the location where raw exhaust
is introduced into the tunnel shall be maintained within ± 1.2 kPa of
atmospheric pressure;
To support mixing the raw exhaust shall be introduced into the tunnel by
directing it downstream along the centreline of the tunnel. A fraction of dilution
air maybe introduced radially from the tunnel's inner surface to minimize
exhaust interaction with the tunnel walls;
Diluent. For PM sampling the temperature of the diluents (ambient air, synthetic
air, or nitrogen as quoted in Paragraph 9.2.1.) shall be maintained within one of
the following ranges (option):
(i)
(ii)
between 293 and 303 K (20 and 30 °C); or
between 293 and 325 K (20 to 52°C); in close proximity to the entrance
into the dilution tunnel. The range shall be selected by the Contracting
Party;
(e)
(f)
The Reynolds number, Re, shall be at least 4000 for the diluted exhaust
stream, where R is based on the inside diameter of the dilution tunnel. Re is
defined in Annexes A.7-A.8. Verification of adequate mixing shall be
performed while traversing a sampling probe across the tunnel's diameter,
vertically and horizontally. If the analyzer response indicates any deviation
exceeding ± 2% of the mean measured concentration, the CVS shall be
operated at a higher flow rate or a mixing plate or orifice shall be installed to
improve mixing;
Flow measurement preconditioning. The diluted exhaust may be conditioned
before measuring its flow rate, as long as this conditioning takes place
downstream of heated HC or PM sample probes, as follows:
(i)
(ii)
(iii)
Flow straighteners, pulsation dampeners, or both of these maybe used;
A filter maybe used;
A heat exchanger maybe used to control the temperature upstream of
any flow meter but steps shall be taken to prevent aqueous
condensation;

9.2.3. Partial Flow Dilution (PFD) System
9.2.3.1. Description of Partial Flow System
A schematic of a PFD system is shown in Figure 9.2. It is a general schematic
showing principles of sample extraction, dilution and PM sampling. It is not meant to
indicate that all the components described in the figure are necessary for other
possible sampling systems that satisfy the intent of sample collection. Other
configurations which do not match these schematics are allowed under the condition
that they serve the same purpose of sample collection, dilution, and PM sampling.
These need to satisfy other criteria such as in Paragraphs 8.1.8.6. (periodic
calibration) and 8.2.1.2. (validation) for varying dilution PFD, and Paragraph 8.1.4.5
as well as Table 8.2 (linearity verification) and Paragraph 8.1.8.5.7. (verification) for
constant dilution PFD.
As shown in Figure 9.2, the raw exhaust gas or the primary diluted flow is transferred
from the exhaust pipe EP or from CVS respectively to the dilution tunnel DT through
the sampling probe SP and the transfer line TL. The total flow through the tunnel is
adjusted with a flow controller and the sampling pump P of the particulate sampling
system (PSS). For proportional raw exhaust sampling, the dilution air flow is
controlled by the flow controller FC1, which may use qmew (exhaust gas mass flow
rate on wet basis) or q (intake air mass flow rate on wet basis) and q (fuel mass
flow rate) as command signals, for the desired exhaust split. The sample flow into the
dilution tunnel DT is the difference of the total flow and the dilution air flow.
The dilution air flow rate is measured with the flow measurement device FM1, the
total flow rate with the flow measurement device of the particulate sampling system.
The dilution ratio is calculated from these two flow rates. For sampling with a
constant dilution ratio of raw or diluted exhaust versus exhaust flow (e.g.: secondary
dilution for PM sampling), the dilution air flow rate is usually constant and controlled
by the flow controller FC1 or dilution air pump.

9.2.3.2. Dilution
The temperature of the diluents (ambient air, synthetic air, or nitrogen as quoted in
Paragraph 9.2.1.) shall be maintained within one of the following ranges (option):
(a)
(b)
between 293 and 303 K (20 and 30 °C); or
between 293 and 325 K (20 to 52°C);
in close proximity to the entrance into the dilution tunnel. The range shall be selected
by the Contracting Party.
De-humidifying the dilution air before entering the dilution system is permitted. The
partial flow dilution system has to be designed to extract a proportional raw exhaust
sample from the engine exhaust stream, thus responding to excursions in the exhaust
stream flow rate, and introduce dilution air to this sample to achieve a temperature at
the test filter as prescribed by Paragraph 9.3.3.4.3. For this it is essential that the
dilution ratio be determined such that the accuracy requirements of
Paragraph 8.1.8.6.1. are fulfilled.
To ensure that a flow is measured that corresponds to a measured concentration,
either aqueous condensation shall be prevented between the sample probe location
and the flow meter inlet in the dilution tunnel or aqueous condensation shall be
allowed to occur and humidity at the flow meter inlet measured. The PFD system
may be heated or insulated to prevent aqueous condensation. Aqueous
condensation shall be prevented throughout the dilution tunnel.
The minimum dilution ratio shall be within the range of 5:1 to 7:1 based on the
maximum engine exhaust flow rate during the test cycle or test interval.
The residence time in the system shall be between 0.5 and 5 s, as measured from the
point of diluent introduction to the filter holder(s).
To determine the mass of the particulates, a particulate sampling system, a
particulate sampling filter, a gravimetric balance, and a temperature and humidity
controlled weighing chamber, are required.
9.2.3.3. Applicability
PFD may be used to extract a proportional raw exhaust sample for any batch or
continuous PM and gaseous emission sampling over any transient duty cycle, any
steady-state duty cycle or any ramped-modal duty cycle.
The system may be used also for a previously diluted exhaust where, via a constant
dilution-ratio, an already proportional flow is diluted (see Figure 9.2). This is the way
of performing secondary dilution from a CVS tunnel to achieve the necessary overall
dilution ratio for PM sampling.

9.3.2. Gas Sampling
9.3.2.1. Sampling Probes
Either single-port or multi-port probes are used for sampling gaseous emissions. The
probes may be oriented in any direction relative to the raw or diluted exhaust flow.
For some probes, the sample temperatures shall be controlled, as follows:
(a)
(b)
For probes that extract NO from diluted exhaust, the probe's wall temperature
shall be controlled to prevent aqueous condensation;
For probes that extract hydrocarbons from the diluted exhaust, a probe wall
temperature is recommended to be controlled approximately 190 ºC to
minimise contamination.
9.3.2.2. Transfer Lines
Transfer lines with inside surfaces of stainless steel, PTFE, Viton , or any other
material that has better properties for emission sampling shall be used. A
non-reactive material capable of withstanding exhaust temperatures shall be used.
In-line filters may be used if the filter and its housing meet the same temperature
requirements as the transfer lines, as follows:
(a)
(b)
For NO transfer lines upstream of either an NO -to-NO converter that meets
the specifications of Paragraph 8.1.11.5. or a chiller that meets the
specifications of Paragraph 8.1.11.4. a sample temperature that prevents
aqueous condensation shall be maintained;
For THC transfer lines a wall temperature tolerance throughout the entire line
of (191 ± 11) °C shall be maintained. If sampled from raw exhaust, an
unheated, insulated transfer line may be connected directly to a probe. The
length and insulation of the transfer line shall be designed to cool the highest
expected raw exhaust temperature to no lower than 191 °C, as measured at
the transfer line outlet. For dilute sampling a transition zone between the probe
and transfer line of up to 0.92 m in length is allowed to transition the wall
temperature to (191 ±11) °C.
9.3.2.3 Sample-Conditioning Components
9.3.2.3.1. Sample dryers
9.3.2.3.1.1. Requirements
The instrument that is used for removing moisture shall meet the minimum
requirements in the following paragraph. The moisture content of 0.8 volume % H O
is used in equation (A.8-14).
For the highest expected water vapour concentration H , the water
removal technique shall maintain CLD humidity at ≤ 5 g water/kg dry air (or about 0.8
volume% H O), which is 100% relative humidity at 3.9 °C and 101.3 kPa. This
humidity specification is also equivalent to about 25% relative humidity at 25 °C and
101.3 kPa. This may be demonstrated by measuring the temperature at the outlet of
a thermal dehumidifier, or by measuring humidity at a point just upstream of the CLD.

9.3.2.3.2. Sample pumps
Sample pumps upstream of an analyzer or storage medium for any gas shall be used.
Sample pumps with inside surfaces of stainless steel, PTFE, or any other material
having better properties for emission sampling shall be used. For some sample
pumps, temperatures shall be controlled, as follows:
(a)
(b)
If a NO sample pump upstream of either an NO -to-NO converter that meets
Paragraph 8.1.11.5. or a chiller that meets Paragraph 8.1.11.4. is used, it shall
be heated to prevent aqueous condensation;
If a THC sample pump upstream of a THC analyzer or storage medium is used,
its inner surfaces shall be heated to a tolerance of (191 ± 11) °C.
9.3.2.4. Sample Storage Media
In the case of bag sampling, gas volumes shall be stored in sufficiently clean
containers that minimally off-gas or allow permeation of gases. Good engineering
judgment shall be used to determine acceptable thresholds of storage media
cleanliness and permeation. To clean a container, it may be repeatedly purged and
evacuated and may be heated. A flexible container (such as a bag) within a
temperature-controlled environment, or a temperature controlled rigid container that is
initially evacuated or has a volume that can be displaced, such as a piston and
cylinder arrangement, shall be used. Containers meeting the specifications in the
following Table 9.1 shall be used.
CO, CO , O ,
CH , C H , C H ,
NO, NO
polyvinyl fluoride (PVF),
for example Tedlar
,
Polyvinylidene fluoride,
for example Kynar
,
polytetrafluoroethylene,
for example Teflon
, or
stainless steel
THC, NMHC
polytetrafluoroethylene
or
stainless steel
Table 9.1
Gaseous Batch Sampling Container Materials

9.3.3.4. Sample Filter
The diluted exhaust shall be sampled by a filter that meets the requirements of
Paragraphs 9.3.3.4.1. to 9.3.3.4.4. during the test sequence.
9.3.3.4.1. Filter Specification
All filter types shall have a 0.3 μm DOP (di-octylphthalate) collection efficiency of at
least 99.7%. The sample filter manufacturer's measurements reflected in their
product ratings may be used to show this requirement. The filter material shall be
either:
(a)
(b)
Fluorocarbon (PTFE) coated glass fibre; or
Fluorocarbon (PTFE) membrane.
9.3.3.4.2. Filter size
If the expected net PM mass on the filter exceeds 400 μg, a filter with a minimum
initial collection efficiency of 98% may be used.
The nominal filter size shall be 46.50 mm ± 0.6 mm diameter.
9.3.3.4.3. Dilution and temperature control of PM samples
PM samples shall be diluted at least once upstream of transfer lines in case of a CVS
system and downstream in case of PFD system (see 9.3.3.2. relating to transfer
lines). Sample temperature is to be controlled to a (47 ± 5) °C tolerance, as
measured anywhere within 200 mm upstream or 200 mm downstream of the PM
storage media. The PM sample is intended to be heated or cooled primarily by
dilution conditions as specified in Paragraph 9.2.1.(a).
9.3.3.4.4. Filter face velocity
A filter face velocity shall be between 0.90 and 1.00 m/s with less than 5% of the
recorded flow values exceeding this range. If the total PM mass exceeds 400 μg, the
filter face velocity may be reduced. The face velocity shall be measured as the
volumetric flow rate of the sample at the pressure upstream of the filter and
temperature of the filter face, divided by the filter's exposed area. The exhaust stack
or CVS tunnel pressure shall be used for the upstream pressure if the pressure drop
through the PM sampler up to the filter is less than 2 kPa.
9.3.3.4.5. Filter holder
To minimize turbulent deposition and to deposit PM evenly on a filter, a 12.5° (from
centre) divergent cone angle to transition from the transfer-line inside diameter to the
exposed diameter of the filter face shall be used. Stainless steel for this transition
shall be used.

9.3.4.5. Installation of Balance
The balance shall be installed as follows:
(a)
(b)
Installed on a vibration-isolation platform to isolate it from external noise and
vibration;
Shielded from convective airflow with a static-dissipating draft shield that is
electrically grounded.
9.3.4.6. Static Electric Charge
Static electric charge shall be minimized in the balance environment, as follows:
(a)
(b)
(c)
(d)
The balance is electrically grounded;
Stainless steel tweezers shall be used if PM samples shall be handled
manually;
Tweezers shall be grounded with a grounding strap, or a grounding strap shall
be provided for the operator such that the grounding strap shares a common
ground with the balance;
A static-electricity neutralizer shall be provided that is electrically grounded in
common with the balance to remove static charge from PM samples.
9.4. Measurement Instruments
9.4.1. Introduction
9.4.1.1. Scope
This paragraph specifies measurement instruments and associated system
requirements related to emission testing. This includes laboratory instruments for
measuring engine parameters, ambient conditions, flow-related parameters, and
emission concentrations (raw or diluted).
9.4.1.2. Instrument Types
Any instrument mentioned in this gtr shall be used as described in the gtr itself
(see Table 8.2 for measurement quantities provided by these instruments).
Whenever an instrument mentioned in this gtr is used in a way that is not specified, or
another instrument is used in its place, the requirements for equivalency provisions
shall apply as specified in Paragraph 5.1.3. Where more than one instrument for a
particular measurement is specified, one of them will be identified by the type
approval or certifying authority upon application as the reference for showing that an
alternative procedure is equivalent to the specified procedure.

9.4.3. Performance Specifications for Measurement Instruments
9.4.3.1. Overview
The test system as a whole shall meet all the applicable calibrations, verifications,
and test-validation criteria specified in Paragraphs 8.1., including the requirements of
the linearity check of Paragraphs 8.1.4. and 8.2. Instruments shall meet the
specifications in Table 9.2 for all ranges to be used for testing. Furthermore, any
documentation received from instrument manufacturers showing that instruments
meet the specifications in Table 9.2 shall be kept.
9.4.3.2. Component Requirements
Table 9.3 shows the specifications of transducers of torque, speed, and pressure,
sensors of temperature and dew point, and other instruments. The overall system for
measuring the given physical and/or chemical quantity shall meet the linearity
verification in Paragraph 8.1.4. For gaseous emissions measurements, analyzers
may be used, that have compensation algorithms that are functions of other
measured gaseous components, and of the fuel properties for the specific engine
test. Any compensation algorithm shall only provide offset compensation without
affecting any gain (that is no bias).
Table 9.3
Recommended Performance Specifications for
Measurement Instruments
Measurement Instrument
Measured
quantity
symbol
Complete
System
Rise time
Recording
update frequency
Accuracy
Engine speed transducer
n
1 s
1 Hz means
2.0% of pt. or
0.5% of max
Engine torque transducer
T
1 s
1 Hz means
2.0% of pt. or
1.0% of max
Fuel flow meter
(Fuel totalizer)
Total diluted exhaust
meter (CVS) (With heat
exchanger before meter)
Dilution air, inlet air,
exhaust, and sample flow
meters
Continuous gas analyzer
raw
Continuous gas analyzer
dilute
5 s
(N/A)
1 s
(5 s)
1 Hz
(N/A)
1 Hz means
(1 Hz)
1 s 1 Hz means of 5 Hz
samples
2.0% of pt. or
1.5% of max
2.0% of pt. or
1.5% of max
2.5% of pt. or
1.5% of max
x
2.5 s
2 Hz
2.0% of pt. or
2.0% of meas.
x
5 s
1 Hz
2.0% of pt. or
2.0% of meas.
Repeatability
1.0% of pt. or
0.25% of max
1.0% of pt. or
0.5% of max
1.0% of pt. or
0.75% of max
1.0% of pt. or
0.75% of max
1.25% of pt. or
0.75% of max
1.0% of pt. or
1.0% of meas.
1.0% of pt. or
1.0% of meas.

9.4.5. Flow-Related Measurements
For any type of flow meter (of fuel, intake-air, raw exhaust, diluted exhaust, sample),
the flow shall be conditioned as needed to prevent wakes, eddies, circulating flows, or
flow pulsations from affecting the accuracy or repeatability of the meter. For some
meters, this may be accomplished by using a sufficient length of straight tubing
(such as a length equal to at least 10 pipe diameters) or by using specially designed
tubing bends, straightening fins, orifice plates (or pneumatic pulsation dampeners for
the fuel flow meter) to establish a steady and predictable velocity profile upstream of
the meter.
9.4.5.1. Fuel Flow Meter
Overall system for measuring fuel flow shall meet the calibration in Paragraph 8.1.8.1.
In any fuel flow measurement it shall be accounted for any fuel that bypasses the
engine or returns from the engine to the fuel storage tank.
9.4.5.2. Intake-Air Flow Meter
Overall system for measuring intake-air flow shall meet the calibration in
Paragraph 8.1.8.2.
9.4.5.3. Raw Exhaust Flow Meter
9.4.5.3.1. Component requirements
The overall system for measuring raw exhaust flow shall meet the linearity
requirements in Paragraph 8.1.4. Any raw-exhaust meter shall be designed to
appropriately compensate for changes in the raw exhaust's thermodynamic, fluid, and
compositional states.
9.4.5.3.2. Flow meter response time
For the purpose of controlling of a partial flow dilution system to extract a proportional
raw exhaust sample, a flow meter response time faster than indicated in Table 9.3 is
required. For partial flow dilution systems with online control, the flow meter response
time shall meet the specifications of Paragraph 8.2.1.2.
9.4.5.3.3. Exhaust cooling
Exhaust cooling upstream of the flow meter is permitted with the following restrictions:
(a)
(b)
PM shall not be sampled downstream of the cooling;
If cooling causes exhaust temperatures above 202 °C to decrease to below
180 °C, NMHC shall not be sampled downstream of the cooling;

9.4.5.4.3. Exhaust cooling
Diluted exhaust upstream of a dilute flow meter may be cooled, as long as all the
following provisions are observed:
(a)
(b)
(c)
(d)
PM shall not be sampled downstream of the cooling;
If cooling causes exhaust temperatures above 202 °C to decrease to below
180 °C, NMHC shall not be sampled downstream of the cooling;
If cooling causes aqueous condensation, NO shall not be sampled
downstream of the cooling unless the cooler meets the performance verification
in Paragraph 8.1.11.4;
If cooling causes aqueous condensation before the flow reaches a flow meter,
dew point, T and pressure p shall be measured at the flow meter inlet.
These values shall be used in emission calculations according
Annexes A.7-A.8.
9.4.5.5. Sample Flow Meter for Batch Sampling
9.4.5.6. Gas Divider
A sample flow meter shall be used to determine sample flow rates or total flow
sampled into a batch sampling system over a test interval. The difference between
two flow meters may be used to calculate sample flow into a dilution tunnel e.g. for
partial flow dilution PM measurement and secondary dilution flow PM measurement.
Specifications for differential flow measurement to extract a proportional raw exhaust
sample is given in Paragraph 8.1.8.6.1. and the calibration of differential flow
measurement is given in Paragraph 8.1.8.6.2.
Overall system for the sample flow meter shall meet the calibration in
Paragraph 8.1.8.
A gas divider may be used to blend calibration gases.
A gas divider shall be used that blends gases to the specifications of Paragraph 9.5.1.
and to the concentrations expected during testing. Critical-flow gas dividers,
capillary-tube gas dividers, or thermal-mass-meter gas dividers may be used.
Viscosity corrections shall be applied as necessary (if not done by gas divider internal
software) to appropriately ensure correct gas division. The gas-divider system shall
meet the linearity verification in Paragraph 8.1.4.5. Optionally, the blending device
may be checked with an instrument which by nature is linear, e.g. using NO gas with
a CLD. The span value of the instrument shall be adjusted with the span gas directly
connected to the instrument. The gas divider shall be checked at the settings used
and the nominal value shall be compared to the measured concentration of the
instrument.

9.4.7.2. Non-Methane Cutter
9.4.7.2.1. Application
A non-methane cutter may be used to measure CH with a FID analyzer. A
non-methane cutter oxidizes all non-methane hydrocarbons to CO and H O. A
non-methane cutter may be used for raw or diluted exhaust for batch or continuous
sampling.
9.4.7.2.2. System performance
Non-methane-cutter performance shall be determined as described in
Paragraph 8.1.10.3. and the results shall be used to calculate NMHC emission in A.7.
and A.8.
9.4.7.2.3. Configuration
The non-methane cutter shall be configured with a bypass line for the verification
described in Paragraph 8.1.10.3.
9.4.7.2.4. Optimization
A non-methane cutter may be optimised to maximize the penetration of CH and the
oxidation of all other hydrocarbons. A sample may be humidified and a sample may
be diluted with purified air or oxygen (O ) upstream of non-methane cutter to optimize
its performance. Any sample humidification and dilution shall be accounted for in
emission calculations.
9.4.7.3. Gas Chromatograph
Application: A gas chromatograph may be used to measure CH concentrations of
diluted exhaust for batch sampling. While also a non-methane cutter may be used to
measure CH , as described in Paragraph 9.4.7.2. a reference procedure based on a
gas chromatograph shall be used for comparison with any proposed alternate
measurement procedure under Paragraph 5.1.3.
9.4.8. NO Measurements
Two measurement instruments are specified for NO measurement and either
instrument may be used provided it meets the criteria specified in Paragraph 9.4.8.1.
or 9.4.8.2., respectively. The chemiluminescent detector shall be used as the
reference procedure for comparison with any proposed alternate measurement
procedure under Paragraph 5.3.
9.4.8.1. Chemiluminescent Detector
9.4.8.1.1. Application
A chemiluminescent detector (CLD) coupled with an NO -to-NO converter is used to
measure NO concentration in raw or diluted exhaust for batch or continuous
sampling.

9.4.8.2.4. Humidity effects
The NDUV temperature shall be maintained to prevent aqueous condensation, unless
one of the following configurations is used:
(a)
(b)
An NDUV shall be connected downstream of any dryer or chiller that is
downstream of an NO -to-NO converter that meets the verification in
Paragraph 8.1.11.5;
An NDUV shall be connected downstream of any dryer or thermal chiller that
meets the verification in Paragraph 8.1.11.4.
9.4.9. O Measurements
A paramagnetic detection (PMD) or magneto pneumatic detection (MPD) analyzer
shall be used to measure O2 concentration in raw or diluted exhaust for batch or
continuous sampling.
9.4.10. Air-To-Fuel Ratio Measurements
A Zirconia (ZrO ) analyser may be used to measure air-to-fuel ratio in raw exhaust for
continuous sampling. O measurements with intake air or fuel flow measurements
may be used to calculate exhaust flow rate according to Annexes A.7-A.8.
9.4.11. PM Measurements with Gravimetric Balance
A balance shall be used to weigh net PM collected on sample filter media.
The minimum requirement on the balance resolution shall be equal or lower than the
repeatability of 0.5 microgram recommended in Table 9.3. If the balance uses
internal calibration weights for routine spanning and linearity verifications, the
calibration weights shall meet the specifications in Paragraph 9.5.2.
The balance shall be configured for optimum settling time and stability at its location.
9.5. Analytical Gases and Mass Standards
9.5.1. Analytical Gases
Analytical gases shall meet the accuracy and purity specifications of this section.

THC
(C equivalent)
Table 9.5
Contamination Limits Applicable for Raw Measurements
[μmol/mol = ppm (3.2.)]
Constituent Purified Synthetic Air Purified N
< 0.05 μmol/mol < 0.05 μmol/mol
CO ≤ 1 μmol/mol` ≤ 1 μmol/mol
CO ≤ 400 μmol/mol ≤ 400 μmol/mol
O 0.18 to 0.21 mol/mol −
NO ≤ 0.1 μmol/mol ≤ 0.1 μmol/mol
(b)
The following gases shall be used with a FID analyzer:
(i) FID fuel shall be used with an H2 concentration of (0.39 to 0.41)
mol/mol, balance He. The mixture shall not contain more than 0.05
μmol/mol THC;
(ii)
(iii)
(iv)
(v)
FID burner air shall be used that meets the specifications of purified air
in Paragraph (a) of this paragraph;
FID zero gas. Flame-ionization detectors shall be zeroed with purified
gas that meets the specifications in Paragraph (a) of this paragraph,
except that the purified gas O concentration may be any value;
FID propane span gas. The THC FID shall be spanned and calibrated
with span concentrations of propane, C H . It shall be calibrated on a
carbon number basis of one (C );
FID methane span gas. If a CH FID is always spanned and calibrated
with a non-methane cutter, then the FID shall be spanned and calibrated
with span concentrations of methane, CH . It shall be calibrated on a
carbon number basis of one (C );
(c)
The following gas mixtures shall be used, with gases traceable within ± 1.0% of
the international and/or national recognized standards true value or of other
gas standards that are approved:
(i)
(ii)
(iii)
CH , balance purified synthetic air and/or N (as applicable);
C H , balance purified synthetic air and/or N (as applicable);
C H , balance purified synthetic air and/or N2 (as applicable);
(iv) CO, balance purified N ;

ANNEX A.1
TEST CYCLES
A.1.1.
Steady-State Discrete-Mode Testing
(a)
For variable-speed engines, the following 8-mode cycle
shall be followed in
dynamometer operation on the test engine:
Mode Number
Engine Speed
Torque [%]
Weighting Factor
1
Rated
100
0.15
2
Rated
75
0.15
3
Rated
50
0.15
4
Rated
10
0.10
5
Intermediate
100
0.10
6
Intermediate
75
0.10
7
Intermediate
50
0.10
8
Idle

0.15
(b)
For constant-speed engines, the following 5-mode cycle 2 shall be followed in
dynamometer operation on the test engine:
Mode Number Engine Speed Torque [%] Weighting Factor
1 Rated 100 0.05
2 Rated 75 0.25
3 Rated 50 0.30
4 Rated 25 0.30
5 Rated 10 0.10
The load figures are percentage values of the torque corresponding to the prime
power rating defined as the maximum power available during a variable power
sequence, which may be run for an unlimited number of hours per year, between
stated maintenance intervals and under the stated ambient conditions, the
maintenance being carried out as prescribed by the manufacturer.

(b)
For constant-speed engines, the following 5-mode duty cycle applies in case of
ramped-modal testing:
RMC mode
Time in
mode [s]
Engine speed Torque (%)
1a Steady-state 53 Engine governed 100
1b Transition 20 Engine governed Linear transition
2a Steady-state 101 Engine governed 10
2b Transition 20 Engine governed Linear transition
3a Steady-state 277 Engine governed 75
3b Transition 20 Engine governed Linear transition
4a Steady-state 339 Engine governed 25
4b Transition 20 Engine governed Linear transition
5 Steady-state 350 Engine governed 50
A.1.3.
Transient Cycle
(a)
For variable-speed engines, the following full transient (variable speed and
variable load) engine dynamometer schedule applies:

Time
Norm.
Speed
Norm.
Torque
Time
Norm.
Norm.
Torque
Time
Norm.
Speed
Norm.
Torque
s % % s % % s % %
142
104
33
189
8
18
236
4
10
143
102
27
190
20
51
237
5
7
144
103
26
191
49
19
238
4
5
145
79
53
192
41
13
239
4
6
146
51
37
193
31
16
240
4
6
147
24
23
194
28
21
241
4
5
148
13
33
195
21
17
242
7
5
149
19
55
196
31
21
243
16
28
150
45
30
197
21
8
244
28
25
151
34
7
198

Time
Norm.
Speed
Norm.
Torque
Time
Norm.
Norm.
Torque
Time
Norm.
Speed
Norm.
Torque
s % % s % % s % %
424
97
62
471
81
73
518
85
73
425
100
53
472
78
73
519
83
73
426
81
58
473
78
73
520
79
73
427
74
51
474
76
73
521
78
73
428
76
57
475
79
73
522
81
73
429
76
72
476
82
73
523
82
72
430
85
72
477
86
73
524
94
56
431
84
60
478
88
72
525
66
48
432
83
72
479
92
71
526
35
71
433
83
72
480
97
54
527
51
44
434
86
72
481
73
43
528
60
23
435
89
72
482
36
64
529
64
10
436
86
72
483
63
31
530
63
14
437
87
72
484
78
1
531
70
37
438
88
72
485
69
27
532
76
45
439
88
71
486
67
28
533
78
18
440
87
72
487
72
9
534
76
51
441
85
71
488
71
9
535
75
33
442
88
72
489
78
36
536
81
17
443
88
72
490
81
56
537
76
45
444
84
72
491
75
53
538
76
30
445
83
73
492
60
45
539
80
14
446
77
73
493
50
37
540
71
18
447
74
73
494
66
41
541
71
14
448
76
72
495
51
61
542
71
11
449
46
77
496
68
47
543
65
2
450
78
62
497
29
42
544
31
26
451
79
35
498
24
73
545
24
72
452
82
38
499
64
71
546
64
70
453
81
41
500
90
71
547
77
62
454
79
37
501
100
61
548
80
68
455
78
35
502
94
73
549
83
53
456
78
38
503
84
73
550
83
50
457
78
46
504
79
73
551
83
50
458
75
49
505
75
72
552
85
43
459
73
50
506
78
73
553
86
45
460
79
58
507
80
73
554
89
35
461
79
71
508
81
73
555
82
61
462
83
44
509
81
73
556
87
50
463
53
48
510
83
73
557
85
55
464
40
48
511
85
73
558
89
49
465
51
75
512
84
73
559
87
70
466
75
72
513
85
73
560
91
39
467
89
67
514
86
73
561
72
3
468
93
60
515
85
73
562
43
25
469
89
73
516
85
73
563
30
60
470
86
73
517
85
72
564
40
45

Time
Norm.
Speed
Norm.
Torque
Time
Norm.
Norm.
Torque
Time
Norm.
Speed
Norm.
Torque
s % % s % % s % %
709
100
68
757
102
49
805
98
90
710
102
71
758
102
42
806
105
94
711
101
64
759
102
52
807
105
100
712
102
69
760
102
57
808
105
98
713
102
69
761
102
55
809
105
95
714
101
69
762
102
61
810
105
96
715
102
64
763
102
61
811
105
92
716
102
69
764
102
58
812
104
97
717
102
68
765
103
58
813
100
85
718
102
70
766
102
59
814
94
74
719
102
69
767
102
54
815
87
62
720
102
70
768
102
63
816
81
50
721
102
70
769
102
61
817
81
46
722
102
62
770
103
55
818
80
39
723
104
38
771
102
60
819
80
32
724
104
15
772
102
72
820
81
28
725
102
24
773
103
56
821
80
26
726
102
45
774
102
55
822
80
23
727
102
47
775
102
67
823
80
23
728
104
40
776
103
56
824
80
20
729
101
52
777
84
42
825
81
19
730
103
32
778
48
7
826
80
18
731
102
50
779
48
6
827
81
17
732
103
30
780
48
6
828
80
20
733
103
44
781
48
7
829
81
24
734
102
40
782
48
6
830
81
21
735
103
43
783
48
7
831
80
26
736
103
41
784
67
21
832
80
24
737
102
46
785
105
59
833
80
23
738
103
39
786
105
96
834
80
22
739
102
41
787
105
74
835
81
21
740
103
41
788
105
66
836
81
24
741
102
38
789
105
62
837
81
24
742
103
39
790
105
66
838
81
22
743
102
46
791
89
41
839
81
22
744
104
46
792
52
5
840
81
21
745
103
49
793
48
5
841
81
31
746
102
45
794
48
7
842
81
27
747
103
42
795
48
5
843
80
26
748
103
46
796
48
6
844
80
26
749
103
38
797
48
4
845
81
25
750
102
48
798
52
6
846
80
21
751
103
35
799
51
5
847
81
20
752
102
48
800
51
6
848
83
21
753
103
49
801
51
6
849
83
15
754
102
48
802
52
5
850
83
12
755
102
46
803
52
5
851
83
9
756
103
47
804
57
44
852
83
8

Time
Norm.
Speed
Norm.
Torque
Time
Norm.
Norm.
Torque
Time
Norm.
Speed
Norm.
Torque
s % % s % % s % %
997
81
23
1045
81
41
1093
102
23
998
83
65
1046
79
46
1094
102
25
999
81
54
1047
80
44
1095
98
42
1000
81
50
1048
84
20
1096
93
68
1001
81
41
1049
79
31
1097
101
25
1002
81
35
1050
87
29
1098
95
64
1003
81
37
1051
82
49
1099
101
35
1004
81
29
1052
84
21
1100
94
59
1005
81
28
1053
82
56
1101
97
37
1006
81
24
1054
81
30
1102
97
60
1007
81
19
1055
85
21
1103
93
98
1008
81
16
1056
86
16
1104
98
53
1009
80
16
1057
79
52
1105
103
13
1010
83
23
1058
78
60
1106
103
11
1011
83
17
1059
74
55
1107
103
11
1012
83
13
1060
78
84
1108
103
13
1013
83
27
1061
80
54
1109
103
10
1014
81
58
1062
80
35
1110
103
10
1015
81
60
1063
82
24
1111
103
11
1016
81
46
1064
83
43
1112
103
10
1017
80
41
1065
79
49
1113
103
10
1018
80
36
1066
83
50
1114
102
18
1019
81
26
1067
86
12
1115
102
31
1020
86
18
1068
64
14
1116
101
24
1021
82
35
1069
24
14
1117
102
19
1022
79
53
1070
49
21
1118
103
10
1023
82
30
1071
77
48
1119
102
12
1024
83
29
1072
103
11
1120
99
56
1025
83
32
1073
98
48
1121
96
59
1026
83
28
1074
101
34
1122
74
28
1027
76
60
1075
99
39
1123
66
62
1028
79
51
1076
103
11
1124
74
29
1029
86
26
1077
103
19
1125
64
74
1030
82
34
1078
103
7
1126
69
40
1031
84
25
1079
103
13
1127
76
2
1032
86
23
1080
103
10
1128
72
29
1033
85
22
1081
102
13
1129
66
65
1034
83
26
1082
101
29
1130
54
69
1035
83
25
1083
102
25
1131
69
56
1036
83
37
1084
102
20
1132
69
40
1037
84
14
1085
96
60
1133
73
54
1038
83
39
1086
99
38
1134
63
92
1039
76
70
1087
102
24
1135
61
67
1040
78
81
1088
100
31
1136
72
42
1041
75
71
1089
100
28
1137
78
2
1042
86
47
1090
98
3
1138
76
34
1043
83
35
1091
102
26
1139
67
80
1044
81
43
1092
95
64
1140
70
67

ANNEX A.2
STATISTICS
A.2.1.
Arithmetic Mean
The arithmetic mean, y , shall be calculated as follows:

y
y =
(A.2-1)
N
A.2.2.
Standard Deviation
The standard deviation for a non-biased (e.g., N–1) sample, σ, shall be calculated as
follows:
σ
=

( y − y )
( N − 1)
(A.2-2)
A.2.3.
Root Mean Square
The root mean square, rms , shall be calculated as follows:
1
rms = ∑ y
(A.2-3)
N
A.2.4.
t-Test
It shall be determined if the data passes a t-test by using the following equations and
tables:
(a) For an unpaired t-test, the t statistic and its number of degrees of freedom, v,
shall be calculated as follows:
y − y
t = (A.2-4)
σ σ
+
N N
⎛ ⎞
⎜ σ σ
+ ⎟
⎜ N N ⎟
⎝ ⎠
V = (A.2-5)
( σ N ) ( σ N)
N − 1
+
N − 1

A.2.5.
F-test
The F statistic shall be calculated as follows:
σ
F =
(A.2-7)
σ
(a)
(b)
For a 90% confidence F-test, Table 2 of this paragraph is used to compare F to
the F values tabulated versus (N−1) and (N −1). If F is less than F ,
then F passes the F-test at 90% confidence;
For a 95% confidence IF-test, Table 3 of this paragraph is used to compare F
to the F values tabulated versus (N−1) and (N −1). If F is less than F ,
then F passes the F-test at 95% confidence.

Table A.2.2 (Continued)

Table A.2.3 (Continued)

ANNEX A.3
1980 INTERNATIONAL GRAVITY FORMULA
The acceleration of Earth's gravity, a , varies depending on the location and a is calculated for a
respective latitude, as follows:
a = 9.7803267715 [1 + 5.2790414 × 10 sin
θ + 1.262 × 10 sin θ + 7 × 10 sin θ]
θ + 2.32718 × 10
sin
(A.3-1)
Where:
θ = Degrees north or south latitude

A.4.2. Carbon Flow Rate into the Engine (Location 1)
The carbon mass flow rate into the engine q [kg/s] for a fuel CH O is given by:
q
12.011
=
12.011 + a + 15.9994
⋅ ε
⋅ q
(A.4-1)
Where:
q
= fuel mass flow rate [kg/s]
A.4.3. Carbon Flow Rate in the Raw Exhaust (Location 2)
The carbon mass flow rate in the exhaust pipe of the engine q [kg/s] shall be
determined from the raw CO concentration and the exhaust gas mass flow rate:
q
⎛ c − c ⎞ 12.011
= ⎜
⋅ q ⋅
100 ⎟
(A.4-2)

⎠ M
Where:
c = wet CO concentration in the raw exhaust gas [per cent]
c = wet CO concentration in the ambient air [%]
q = exhaust gas mass flow rate on wet basis [kg/s]
M
= molar mass of exhaust gas [g/mol]
If CO is measured on a dry basis it shall be converted to a wet basis according to
Paragraph A.7.3.2. or A.8.2.2.

ANNEX A.5
INSTALLATION REQUIREMENTS FOR EQUIPMENT AND AUXILIARIES
Number Equipment and auxiliaries Fitted for emission test
1 Inlet system
Inlet manifold
Crankcase emission control system
Air flow meter
Air filter
Inlet silencer
2 Exhaust system
Exhaust after-treatment
Exhaust manifold
Connecting pipes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Silencer
Tail pipe
Exhaust brake
Pressure charging device
Yes
Yes
No
Yes
3 Fuel supply pump Yes
4 Fuel injection equipment
Prefilter
Filter
Pump
5 High-pressure pipe
Injector
Electronic control unit, sensors, etc.
Governor/control system
Automatic full-load stop for the control rack
depending on atmospheric conditions
6 Liquid-cooling equipment
Radiator
Fan
Fan cowl
Water pump
Thermostat
7 Air cooling
Cowl
Fan or Blower
Temperature-regulating device
8 Pressure charging equipment
Compressor driven either directly by the
engine and/or by the exhaust gases
Charge air cooler
Coolant pump or fan (engine-driven)
Coolant flow control device
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
No
No
No
Yes
Yes
No
Yes

ANNEX A.6
DIESEL REFERENCE FUELS
A.6.1.
European Union Diesel Reference Fuel
Parameter
Cetane number
Density at 15 °C
Distillation:
− 50% vol
− 95% vol.
− final boiling point
Flash point
Cold filter plugging point
Kinematic viscosity at 40 °C
Polycylic aromatic
hydrocarbons
Conradson carbon residue (10%
DR)
Unit
kg/m
°C
°C
°C
°C
°C
mm /
%
m/m
%
m/m
Ash content %
m/m
Water content %
m/m
Minimum
52
833
Limits
Maximum
54
837
245
345 350
370
55
2.3
2.0
-5
3.3
6.0
Test method
ISO 5165
ISO 3675
ISO 3405
ISO 2719
EN 116
ISO 3104
EN 12916
0.2 ISO 10370
0.01 EN-ISO 6245
0.02 EN-ISO 12937
Sulphur content mg/kg 10 EN-ISO 14596
Copper corrosion at 50 °C 1 EN-ISO 2160
Lubricity (HFRR at 60 °C) μm 400 CEC F-06-A-96
Neutralisation number mg KOH/g 0.02
Oxidation stability mg/ml 0.025 EN-ISO 12205

ANNEX A.7
MOLAR BASED EMISSION CALCULATIONS
A.7.0.
A.7.0.1.
Symbol Conversion
General Symbols
Annex 7
Annex 8
Unit
Quantity
A
m
Area
A
m
Venturi throat cross-sectional area
a
b, D
t.b.d.
γ intercept of the regression line, PDP calibration
intercept
a
m
t.b.d.
Slope of the regression line
β
r
m/m
Ratio of diameters
C

Coefficient
C
C

Discharge coefficient
C

Flow coefficient
d
d
m
Diameter
DR
r

Dilution ratio
e
e
g/kWh
Brake specific basis
e
e
g/kWh
Specific emission of gaseous components
e
e
g/kWh
Specific emission of particulates
f
Hz
Frequency
f
n
min , s
Rotational frequency (shaft)
γ

Ratio of specific heats
K
Correction factor
K
X
s/rev
PDP slip correction factor
k
k

Downward adjustment factor
k
Humidity correction factor for NO
k
k

Multiplicative regeneration factor
k
k

Upward adjustment factor
μ
μ
kg/(m·s)
Dynamic viscosity
M
M
g/mol
Molar mass
M
M
g/mol
Molar mass of gaseous components
m
m
kg
Mass
m
q
kg/s
Mass rate
ν
m /
Kinematic viscosity
N
Total number in series
n
mol
Amount of substance
n
mol/s
Amount of substance rate

A.7.0.2.
Subscripts
Annex 7
Annex 8 (1)
Quantity
abs
Absolute quantity
act
act
Actual quantity
air
Air, dry
atmos
Atmospheric
bkgnd
Background
C
Carbon
cal
Calibration quantity
CFV
Critical flow venturi
cor
Corrected quantity
dil
Dilution air
dexh
Diluted exhaust
dry
Dry quantity
exh
Raw exhaust
exp
Expected quantity
eq
Equivalent quantity
fuel
Fuel
i
Instantaneous measurement (e.g.: 1 Hz)
i
An individual of a series
idle
Condition at idle
in
Quantity in
init
Initial quantity, typically before an emission test
max
Maximum (i.e. peak) value
meas
Measured quantity
min
Minimum value
mix
Molar mass of air
out
Quantity out
part
Partial quantity
PDP
Positive displacement pump
raw
Raw exhaust
ref
Reference quantity
rev
Revolution
sat
Saturated condition
slip
PDP slip
smpl
Sampling
span
Span quantity
SSV
Subsonic venture
std
Standard quantity
test
Test quantity
total
Total quantity
uncor
Uncorrected quantity
vac
Vacuum quantity
weight
Calibration weight
wet
Wet quantity
zero
Zero quantity

A.7.0.5. Symbols for Chemical Balance used in Annex 7
x = Amount of dilution gas or excess air per mole of exhaust
x = Amount of water in exhaust per mole of exhaust
x = Amount of carbon from fuel in the exhaust per mole of dry exhaust
x = Amount of water in exhaust per dry mole of dry exhaust
x = Amount of dry stoichiometric products per dry mole of intake air
x = Amount of dilution gas and/or excess air per mole of dry exhaust
x = Amount of intake air required to produce actual combustion
products per mole of dry (raw or diluted) exhaust
x = Amount of undiluted exhaust, without excess air, per mole of dry
(raw or diluted) exhaust
x = Amount of intake air O per mole of dry intake air
x = Amount of intake air CO per mole of dry intake air
x = Amount of intake air H O per mole of dry intake air
x = Amount of intake air CO per mole of intake air
x = Amount of dilution gas CO per mole of dilution gas
x = Amount of dilution gas CO per mole of dry dilution gas
x = Amount of dilution gas H O per mole of dry dilution gas
x = Amount of dilution gas H O per mole of dilution gas
x = Amount of measured emission in the sample at the respective gas
analyzer
x = Amount of emission per dry mole of dry sample
x = Amount of water in sample at emission-detection location
x = Amount of water in the intake air, based on a humidity
measurement of intake air
A.7.1.
A.7.1.1.
Basic Parameters and Relationships
Dry air and Chemical Species
This annex uses the following values for dry air composition:
X
X
0.209445mol/mol
0.000375 mol/mol
This annex uses the following molar masses or effective molar masses of chemical
species:
M = 28.96559 g/mol (dry air)
M = 39.948 g/mol (argon)
M = 12.0107 g/mol (carbon)
M = 28.0101 g/mol (carbon monoxide)
M = 44.0095 g/mol (carbon dioxide)
M = 1.00794 g/mol (atomic hydrogen)
M = 2.01588 g/mol (molecular hydrogen)
M = 18.01528 g/mol (water)
M = 4.002602 g/mol (helium)
M = 14.0067 g/mol (atomic nitrogen)
M = 28.0134 g/mol (molecular nitrogen)

(b)
For humidity measurements made over ice at ambient temperatures from
(- 100 to 0) °C:
log
( P
⎛ 273.16 ⎞
) = 9.096853 ⋅
⎜ − 1
⎟ − 3.566506 ⋅ log
⎝ T ⎠
⎛ 273.16 ⎞
⎛ T ⎞

⎟ + 0.876812 ⋅ ⎜1
− ⎟ − 0.2138602
⎝ T ⎠
⎝ 273.16 ⎠
(A.7-2)
Where:
T = saturation temperature of water at measured condition [K]
A.7.1.2.2.
Dew Point
If humidity is measured as a dew point, the amount of water in an ideal gas x
[mol/mol] shall be obtained as follows:
Where:
x = amount of water in an ideal gas [mol/mol]
P
x = (A.7-3)
P
p = vapour pressure of water at the measured dew point, T = T [kPa]
p
= wet static absolute pressure at the location of dew point measurement [kPa]
A.7.1.2.3.
Relative Humidity
If humidity is measured as a relative humidity RH%, the amount of water of an ideal
gas x [mol/mol] is calculated as follows:
x
RH% P
= ⋅
(A.7-4)
100 P
Where:
RH% = relative humidity [%]
p = water vapour pressure at 100% relative humidity at the location of
relative humidity measurement, T = T [kPa]
p
=
wet static absolute pressure at the location of relative humidity
measurement [kPa]

A.7.1.4.2.
NMHC Determination
To determine NMHC concentration, x
, one of the following shall be used:
(a)
If CH is not measured, NMHC concentrations may be determined as follows:
The background corrected mass of NMHC shall be compared to background
corrected mass of THC. If the background corrected mass of NMHC is greater
than 0.98 times the background corrected mass of THC, the background
corrected mass of NMHC shall be taken as 0.98 times the background
corrected mass of THC. If the NMHC calculations are omitted, the background
corrected mass of NMHC shall be taken as 0.98 times the background
corrected mass of THC;
(b) For non-methane cutters, x shall be calculated using the non-methane
cutter's penetration fractions (PF) of CH and C H from Paragraph 8.1.10.3.,
and using the HC contamination and dry-to-wet corrected THC concentration
x as determined in subparagraph (a) of A.7.1.4.1.;
(i)
The following equation for penetration fractions determined using an
NMC configuration as outlined in Paragraph 8.1.10.3.4.1. shall be used:
x [ ] − x [ ] ⋅ RF [ ]
x =
(A.7-6)
1 − RFPF [ ] ⋅ RF [ ]
Where:
x = concentration of NMHC
x
=
concentration of THC, HC contamination and
dry-to-wet corrected, as measured by the THC
FID during sampling while bypassing the NMC
x = concentration of THC, HC contamination
(optional) and dry-to-wet corrected, as measured
by the NMC FID during sampling through the
NMC
RF
=
response factor of THC FID to CH , according to
Paragraph 8.1.10.1.4.
RFPF
=
non-methane cutter combined ethane response
factor and penetration fraction, according to
Paragraph 8.1.10.3.4.1.

(c) For a gas chromatograph, x shall be calculated using the THC analyzer's
response factor (RF) for CH , from Paragraph 8.1.10.1.4., and the
HC contamination and wet-to-dry corrected initial THC concentration
x as determined in Paragraph (a) above as follows:
x
= x
− RF
⋅ x
(A.7-9)
Where:
x = concentration of NMHC
x
=
concentration of THC, HC contamination and dry-to-wet
corrected, as measured by the THC FID
x = concentration of CH , HC contamination (optional) and
dry-to-wet corrected, as measured by the gas chromatograph
FID
RF = response factor of THC-FID to CH
A.7.1.4.3.
Approximation of NMHC from THC
NMHC (non-methane hydrocarbon) emissions can be approximated as 98% of THC
(total hydrocarbon).
A.7.1.5.
Flow-Weighted Mean Concentration
In some paragraphs of this annex, it may be necessary to calculate a flow-weighted
mean concentration to determine the applicability of certain provisions. A
flow-weighted mean is the mean of a quantity after it is weighted proportional to a
corresponding flow rate. For example, if a gas concentration is measured
continuously from the raw exhaust of an engine, its flow-weighted mean concentration
is the sum of the products of each recorded concentration times its respective
exhaust molar flow rate, divided by the sum of the recorded flow rate values. As
another example, the bag concentration from a CVS system is the same as the
flow-weighted mean concentration because the CVS system itself flow-weights the
bag concentration. A certain flow-weighted mean concentration of an emission at its
standard might be already expected based on previous testing with similar engines or
testing with similar equipment and instruments.
A.7.2.
A.7.2.1.
Chemical Balances of Fuel, Intake Air, and Exhaust
General
Chemical balances of fuel, intake air and exhaust may be used to calculate flows, the
amount of water in their flows, and the wet concentration of constituents in their flows.
With one flow rate of either fuel, intake air or exhaust, chemical balances may be
used to determine the flows of the other two. For example, chemical balances along
with either intake air or fuel flow to determine raw exhaust flow may be used.

(b)
(c)
Equations (A.7-10 to A.7-26) in Paragraph (d) of this paragraph A.7.2.3. have
to be entered into a computer program to iteratively solve for x , x
and x . Good engineering judgment shall be used to guess initial values for
x , x , and x . Guessing an initial amount of water that is about
twice the amount of water in your intake or dilution air is recommended.
Guessing an initial value of x as the sum of your measured CO , CO,
and THC values is recommended. Guessing an initial x between 0.75 and
0.95 (0.75 < x < 0.95), such as 0.8 is also recommended. Values in the
system of equations shall be iterated until the most recently updated guesses
are all within ± 1% of their respective most recently calculated values;
The following symbols and subscripts are used in the equation system of
Paragraph (c) of this paragraph where x unit is mol/mol:
Symbol
Description
x
Amount of dilution gas or excess air per mole of exhaust
x
Amount of H O in exhaust per mole of exhaust
x
Amount of carbon from fuel in the exhaust per mole of dry exhaust
x
Amount of water in exhaust per dry mole of dry exhaust
x
Amount of dry stoichiometric products per dry mole of intake air
x
Amount of dilution gas and/or excess air per mole of dry exhaust
x
Amount of intake air required to produce actual combustion products per mole
of dry (raw or diluted) exhaust
x
Amount of undiluted exhaust, without excess air, per mole of dry (raw or
diluted) exhaust
x
Amount of intake air O per mole of dry intake air; x
= 0.209445 mol/mol
may be assumed
x
Amount of intake air CO per mole of dry intake air. x
= 375 mmol/mol
may be used, but measuring the actual concentration in the intake air is
recommended
x
Amount of the intake air H O per mole of dry intake air
x
Amount of intake air CO per mole of intake air
x
Amount of dilution gas CO per mole of dilution gas
x
Amount of dilution gas CO per mole of dry dilution gas. If air is used a
diluent, x
= 375 mmol/mol may be used, but measuring the actual
concentration in the intake air is recommended
x
Amount of dilution gas H O per mole of dry dilution gas
x
Amount of dilution gas H O per mole of dilution gas
x
Amount of measured emission in the sample at the respective gas analyzer
x
Amount of emission per dry mole of dry sample
x
Amount of water in sample at emission-detection location. These values shall
be measured or estimated according to Paragraph 9.3.2.3.1.
x
Amount of water in the intake air, based on a humidity measurement of intake
air
a
Atomic hydrogen-to-carbon ratio of the mixture of fuel(s) (CH O ) being
combusted, weighted by molar consumption
β
Atomic oxygen-to-carbon ratio of the mixture of fuel(s) (CH O ) being
combusted, weighted by molar consumption

x
x
x
x
x
=
1 − x
(A.7-23)
x
=
1 − x
(A.7-24)
x
=
1 − x
(A.7-25)
x
=
1 − x
(A.7-26)
At the end of the chemical balance, the molar flow rate n is calculated as specified
in Paragraphs A.7.3.3. and A.7.4.3.
A.7.2.4.
NO Correction for Humidity
All the NO concentrations, including dilution air background concentrations, shall be
corrected for intake-air humidity using the following equation:
Where:
( 9 .953 ⋅ + 0.832)
x = x ⋅ x
(A.7-27)
x = uncorrected NO molar concentration in the exhaust gas [μmol/mol]
x = amount of water in the intake air [mol/mol]
A.7.3.
A.7.3.1.
Raw Gaseous Emissions
Mass of Gaseous Emissions
To calculate the total mass per test of gaseous emission m [g/test], its molar
concentration shall be multiplied by its respective molar flow and by exhaust gas
molar mass; then integration over test cycle shall be performed:
m
= M ⋅ ∫ n ⋅ x ⋅ dt
(A.7-28)
Where:
M = molar mass of the generic gaseous emission [g/mol]
n = instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x = instantaneous generic gas molar concentration on a wet basis [mol/mol]
t = time [s]

(b)
Still for continuous sampling but in the particular case of constant flow rate the
mass of the gaseous emission m [g/test] shall be calculated by means of the
following equation:
m
= M ⋅ n ⋅ x ⋅ Δt
(A.7-31)
Where:
M = generic emission molar mass [g/mol]
n = exhaust gas molar flow rate on a wet basis [mol/s]
x = mean gaseous emission molar fraction on a wet basis [mol/mol]
Δt = time duration of test interval
(c)
For the batch sampling, regardless the flow rate is varying or constant, the
equation (A.7-30) can be simplified as follows:
Where:
m
1
= ⋅ M ⋅ x ⋅ ∑ n
ƒ
(A.7-32)
M = generic emission molar mass [g/mol]
n
=
instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x
=
mean gaseous emission molar fraction on a wet basis [mol/mol]
ƒ
=
data sampling rate [Hz]
N
=
number of measurements [-]

A.7.3.3.
Exhaust Gas Molar Flow Rate
The flow rate of the raw exhaust gases can be directly measured or can be calculated
based on the chemical balance of Paragraph A.7.2.3. Calculation of raw exhaust
molar flow rate is performed from measured intake air molar flow rate or fuel mass
flow rate. The raw exhaust molar flow rate can be calculated from the sampled
emissions, n , based on the measured intake air molar flow rate, n , or the
measured fuel mass flow rate, fuel, m and the values calculated using the chemical
balance in Paragraph A.7.2.3. It shall be solved for the chemical balance in
Paragraph A.7.2.3. at the same frequency that n or m is updated and recorded.
(a) Crankcase flow rate. The raw exhaust flow can be calculated based on n or
m only if at least one of the following is true about crankcase emission flow
rate:
(i)
(ii)
(iii)
(iv)
The test engine has a production emission-control system with a closed
crankcase that routes crankcase flow back to the intake air, downstream
of intake air flow meter;
During emission testing open crankcase flow are routed to the exhaust
according to Paragraph 6.10;
Open crankcase emissions and flow are measured and added
brake-specific emission calculations;
Using emission data or an engineering analysis, it can be demonstrated
that neglecting the flow rate of open crankcase emissions does not
adversely affect compliance with the applicable standards;
(b) Molar flow rate calculation based on intake air. Based on n , exhaust gas
molar flow rate n [mol/s] shall be calculated as follows:
Where:
n
n =
(A.7-36)

⎢1
+
⎢⎣
( x − x )
( ) ⎥ ⎥ ⎤
1 + x

n
n
= raw exhaust molar flow rate from which emissions are
measured [mol/s]
= intake air molar flow rate including humidity in intake air [mol/s]
x
=
amount of intake air required to produce actual combustion
products per mole of dry (raw or diluted) exhaust [mol/mol]
x
=
amount of undiluted exhaust, without excess air, per mole of
dry (raw or diluted) exhaust [mol/mol]
x = amount of water in exhaust per mole of dry exhaust [mol/mol]

Continuous sampling, constant flow rate
m
= M ⋅ n ⋅ x ⋅ Δt
(see A.7-31)
Where:
M = generic emission molar mass [g/mol]
n = exhaust gas molar flow rate on a wet basis [mol/s]
x = mean gaseous emission molar fraction on a wet basis [mol/mol]
∆t = time duration of test interval
(b)
Batch sampling, regardless varying flow or constant rate is, the following
equation shall be used:
1
m = ⋅ M ⋅ x ⋅ ∑ n
(see A.7-32)
ƒ
Where:
M = generic emission molar mass [g/mol]
n = instantaneous exhaust gas molar flow rate on a wet basis [mol/s]
x = mean gaseous emission molar fraction on a wet basis [mol/mol]
f = data sampling rate [Hz]
N = Number of measurements [-]

Considering the two cases (v) and (vi), the following equations shall be used:
m
= M ⋅ x ⋅ n or m = M ⋅ x ⋅ x ⋅ n
(A.7-38)
m
= m − m
(A.7-39)
Where:
m
=
total mass of the gaseous emission [g]
m
=
total background masses [g]
m
=
mass of gas corrected for background emissions [g]
M
=
molecular mass of generic gaseous emission [g/mol]
x
=
gaseous emission concentration in dilution air [mol/mol]
n
=
dilution air molar flow [mol]
x
=
flow-weighted mean fraction of dilution air in diluted exhaust [mol/mol]
x
=
gas fraction of background [mol/mol]
n
=
total flow of diluted exhaust [mol]
A.7.4.2.
Dry-to-wet Concentration Conversion
The same relations for raw gases (Paragraph A.7.3.2.) shall be used for dry-to-wet
conversion on diluted samples. For dilution air a humidity measurement shall be
performed with the aim to calculate its water vapour fraction x [mol/mol]:
Where:
x = water molar fraction in the dilution air flow [mol/mol]

Where:
V
a P − P
= ⋅
ƒ
P
+ a
(A.7-41)
Where:
a
=
calibration coefficient [m /s]
a
=
calibration coefficient [m /rev]
p , p
=
inlet/outlet pressure [Pa]
R
=
molar gas constant [J/(mol K)]
T
=
inlet temperature [K]
V
=
PDP pumped volume [m /rev]
f
=
PDP speed [rev/s]
(ii)
SSV molar flow rate. Based on the C versus R
equation determined
according to Appendix 1 of this annex, the Sub-Sonic Venturi (SSV)
molar flow rate during an emission test n [mol/s] shall be calculated as
follows:
n = C
⋅ C

A
⋅ P
(A.7-42)
Z ⋅ M
⋅ R ⋅ T
Where:
p
=
inlet pressure [Pa]
A
=
Venturi throat cross-sectional area [m ]
R
=
molar gas constant [J/(mol K)]
T
=
inlet temperature [K]
Z
=
compressibility factor
M
=
molar mass of diluted exhaust [kg/mol]
C
=
discharge coefficient of the SSV [-]
C
=
flow coefficient of the SSV [-]

(b)
Sampling from a Constant Flow Rate
If a batch sample from a constant exhaust flow rate is collected, the mean
molar flow rate from which the sample is extracted shall be determined. The
mean PM concentration shall be multiplied by the total flow to obtain the total
mass of PM m [g]:
m
= M ⋅ n ⋅ Δt
(A.7-45)
Where:
n
M
= exhaust molar flow rate [mol/s]
= mean PM concentration [g/mol]
Δ = time duration of test interval [s]
For sampling with a constant dilution ratio (DR), m [g] shall be calculated
using the following equation:
Where:
m = m ⋅ DR (A.7-46)
m = PM mass in dilution air [g]
DR
= dilution ratio [-] defined as the ratio between the mass of the
emission
m
and
the
mass
of
diluted
exhaust
m
(DR = m/m
).
The dilution ratio DR can be expressed as a function of x :
1
DR = 1 − x
(A.7-47)
A.7.4.4.2.
Background Correction
The same approach as that of Paragraph A.7.4.1. shall be applied to correct the
mass of PM for the background. Multiplying M by the total flow of dilution air,
the total background mass of PM (m [g]) is obtained. Subtraction of total
background mass from total mass gives background corrected mass of particulates
m [g]:
m
= m − M ⋅ n
(A.7-48)
Where:
m = uncorrected PM mass [g]
M
= mean PM concentration in dilution air [g/mol]
n = dilution air molar flow [mol]

A.7.5.1.2.
Steady-State Discrete-Mode Cycle
The specific emissions e [g/kWh] are calculated as follows:
⎛ ⎞
∑ ⎜m
⋅ WF ⎟
⎝ ⎠
e =
(A.7-52)

( P ⋅ WF )
Where:
m = mean emission mass flow rate for the mode i [g/h]
P
=
engine power for the mode i [kW] with P = P
+ P
(see Paragraphs 7.7.1.2. and 6.3.)
WF = weighting factor for the mode i [-]
A.7.5.2.
A.7.5.2.1.
Particulate Emissions
Transient and Ramped Modal Cycles
The particulate specific emissions shall be calculated with equation (A.7-50) where
e [g/kWh] and m [g/test] are substituted by e [g/kWh] and m [g/test]
respectively:
Where:
m
e = (A.7-53)
W
m = total mass of particulates emission, calculated according to
Paragraph A.8.3.4. [g/test]
W = cycle work [kWh]
The emissions on the transient composite cycle (i.e. cold phase and hot phase) shall
be calculated as shown in Paragraph A.7.5.1.
A.7.5.2.2.
Steady State Discrete-Mode Cycle
The particulate specific emission e [g/kWh] shall be calculated in the following way:

ANNEX A.7. - APPENDIX 1
DILUTED EXHAUST FLOW (CVS) CALIBRATION
A.7.6.
Introduction
This Appendix 1 describes the calculations for calibrating various flow meters.
Paragraph A.7.6.1. of this Appendix 1 first describes how to convert reference flow
meter outputs for use in the calibration equations, which are presented on a molar
basis. The remaining paragraphs describe the calibration calculations that are
specific to certain types of flow meters.
A.7.6.1.
Reference Meter Conversions
The calibration equations in this section use molar flow rate, n , as a reference
quantity. If he adopted reference meter outputs a flow rate in a different quantity,
such as standard volume rate, V , actual volume rate, V ,or mass rate , m ,
the reference meter output shall be converted to a molar flow rate using the following
equations, noting that while values for volume rate, mass rate, pressure, temperature,
and molar mass may change during an emission test, they should be kept as
constant as practical for each individual set-point during a flow meter calibration:
V ⋅ P V ⋅ P m
n = =
=
(A.7-57)
T ⋅ R T ⋅ R M
Where:
n
V
V
m
= reference molar flow rate [mol/s]
= reference volume flow rate, corrected to a standard pressure and a
standard temperature [m /s]
= reference volume flow rate, at the actual pressure and temperature
[m /s]
= reference mass flow [g/s]
p
=
standard pressure [Pa]
p
=
actual pressure of the gas [Pa]
T
=
standard temperature [K]
T
=
actual temperature of the gas [K]
R
=
molar gas constant [J/(mol ⋅ K)]
M
=
molar mass of the gas [g/mol]

(c) A least-squares regression of PDP volume pumped per revolution, V , versus
PDP slip correction factor, K , shall be performed by calculating slope, a , and
intercept, a , as described in Annex A.2;
(d)
The procedure in subparagraphs (a) through (c) of this paragraph shall be
repeated for every speed that PDP is operated;
(e)
The following table illustrates these calculations for different values of
ƒ
:
Table A.7.2
Example of PDP Calibration Data
(f)
ƒ
[rev/min] ƒ [rev/s] a [m /min] a [m /s] a [m /rev]
755.0 12.58 50.43 0.8405 0.056
987.6 16.46 49.86 0.831 - 0.013
1254.5 20.9 48.54 0.809 0.028
1401.3 23.355 47.30 0.7883 - 0.061
For each speed at which the PDP is operated, the corresponding slope, a , and
intercept, a , shall be used to calculate flow rate during emission testing as
described in Paragraph A.7.4.3.(b).
A.7.6.3.
Venturi Governing Equations and Permissible Assumptions
This section describes the governing equations and permissible assumptions for
calibrating a venturi and calculating flow using a venturi. Because a subsonic venturi
(SSV) and a critical-flow venturi (CFV) both operate similarly, their governing
equations are nearly the same, except for the equation describing their pressure ratio,
r (i.e., r versus r ). These governing equations assume one-dimensional
isentropic inviscid compressible flow of an ideal gas. In Paragraph A.7.6.3.(d) of this
section, other assumptions that may be made are described. If the assumption of an
ideal gas for the measured flow is not allowed, the governing equations include a
first-order correction for the behaviour of a real gas; namely, the compressibility
factor, Z. If good engineering judgment dictates using a value other than Z = 1, an
appropriate equation of state to determine values of Z as a function of measured
pressures and temperatures may be used, or specific calibration equations may be
developed based on good engineering judgment. It shall be noted that the equation
for the flow coefficient, C , is based on the ideal gas assumption that the isentropic
exponent, γ, is equal to the ratio of specific heats, c /c . If good engineering
judgment dictates using a real gas isentropic exponent, an appropriate equation of
state to determine values of γ as a function of measured pressures and temperatures
may be used, or specific calibration equations may be developed. Molar flow rate,
n [mol/s], shall be calculated as follows:

Table A.7.3
C
Versus β and γ for CFV Flow Meters
C
β
γ
=1.385
γ
= γ =1.399
0.000
0.6822
0.6846
0.400
0.6857
0.6881
0.500
0.6910
0.6934
0.550
0.6953
0.6977
0.600
0.7011
0.7036
0.625
0.7047
0.7072
0.650
0.7089
0.7114
0.675
0.7137
0.7163
0.700
0.7193
0.7219
0.720
0.7245
0.7271
0.740
0.7303
0.7329
0.760
0.7368
0.7395
0.770
0.7404
0.7431
0.780
0.7442
0.7470
0.790
0.7483
0.7511
0.800
0.7527
0.7555
0.810
0.7573
0.7602
0.820
0.7624
0.7652
0.830
0.7677
0.7707
0.840
0.7735
0.7765
0.850
0.7798
0.7828

(iv)
For the full range of diluted exhaust and air, the molar mass of the
mixture, M [g/mol], may be considered as a function only of the
amount of water in the dilution air or calibration air, x , determined as
described in Paragraph A.7.1.2., as follows:
(M
= M ⋅ (1- x
) + M
⋅ (x
)
(A.7-65)
Where:
M
=
28.96559 g/mol
M
=
18.01528 g/mol
x
=
amount of water in the dilution or calibration air [mol/mol]
(v)
For the full range of diluted exhaust and air, a constant molar mass of
the mixture, M , may be assumed for all calibration and all testing as
long as assumed molar mass differs no more than ±1% from the
estimated minimum and maximum molar mass during calibration and
testing. This assumption may be made if sufficient control of the amount
of water in calibration air and in dilution air is ensured, or if sufficient
water is removed from both calibration air and dilution air. The following
table gives examples of permissible ranges of dilution air dew point
versus calibration air dew point:
Table A.7.4
Examples of Dilution Air and Calibration Air Dew Points
at which a Constant M May Be Assumed
If calibration T
(°C) is...
the following constant
for the following ranges of T
(°C)
M
(g/mol) is assumed
during emission tests
dry
28.96559
dry to 18

Gas
Table A.7.5
Sutherland Three-Coefficient Viscosity Model Parameters
μ T S
Temp range within
± 2% error
Pressure limit
kg/(m·s) K K K kPa
Air 1.716 x 10 273 111 170 to 1900 ≤ 1800
CO 1.370 x 10 273 222 190 to 1700 ≤ 3600
H O 1.12 x 10 350 1,064 360 to 1500 ≤ 10000
O 1.919 x 10 273 139 190 to 2000 ≤ 2500
N 1.663 x 10 273 107 100 to 1500 ≤ 1600
(ii)
An equation for C versus Re shall be created, using paired values of
(Re , C ). C is calculated according to equation (A.7-61), with C
obtained from equation (A.7-62), or any mathematical expression may
be used, including a polynomial or a power series. The following
equation is an example of a commonly used mathematical expression for
relating C and Re ;
10
C = a − a ⋅
(A.7-68)
Re
(iii)
A least-squares regression analysis shall be performed to determine the
best-fit coefficients to the equation and calculate the equation's
regression statistics, the standard estimate error SEE and the coefficient
of determination r , according to Annex A.2;
(iv) If the equation meets the criteria of SEE < 0.5% ⋅ n (or m )
and r ≥ 0.995, the equation may be used to determine C for emission
tests, as described in A.7.4.3.(b);
(v)
If the SEE and r criteria are not met, good engineering judgment may be
used to omit calibration data points to meet the regression statistics. At
least seven calibration data points shall be used to meet the criteria;

(vi)
(vii)
If the number of remaining C values is seven or greater, the mean and
standard deviation of the remaining C values shall be recalculated;
If the standard deviation of the remaining C values is less than or equal to
0.3% of the mean of the remaining C , that mean C shall be used in equation
(A.7-43) and the CFV values only down to the lowest r associated with the
remaining C shall be used;
(viii) If the standard deviation of the remaining C still exceeds 0.3% of the mean of
the remaining C values, the steps in Paragraph (e) (4) through (8) of this
section shall be repeated.

A.7.7.4.
Drift Correction
All gas analyzer signals shall be corrected as follows:
(a)
Each recorded concentration, xi, shall be corrected for continuous sampling or
for batch sampling, x ;
x
(b) Correction for drift shall be done using the following equation:
2x
− ( x + x )
( x − x )
( x + x ) − ( x + x )
= x +
(A.7-70)
Where:
x = concentration corrected for drift [μmol/mol]
x
=
reference concentration of the zero gas, which is usually zero
unless known to be otherwise [μmol/mol]
x = reference concentration of the span gas [μmol/mol]
x
=
pre-test interval gas analyzer response to the span gas
concentration [μmol/mol]
x
=
post-test interval gas analyzer response to the span gas
concentration [μmol/mol]
x or x
=
concentration recorded, i.e. measured, during test, before drift
correction [μmol/mol]
x
=
pre-test interval gas analyzer response to the zero gas
concentration [μmol/mol]
x
=
post-test interval gas analyzer response to the zero gas
concentration [μmol/mol]
(c)
(d)
For any pre-test interval concentrations, concentrations determined most
recently before the test interval shall be used. For some test intervals, the
most recent pre-zero or pre-span might have occurred before one or more
previous test intervals;
For any post-test interval concentrations, concentrations determined most
recently after the test interval shall be used. For some test intervals, the most
recent post-zero or post-span might have occurred after one or more
subsequent test intervals;
(e) If any pre-test interval analyzer response to the span gas concentration, x ,
is not recorded, x shall be set equal to the reference concentration of the
span gas: x = x ;

ANNEX A.8
MASS BASED EMISSION CALCULATIONS
A.8.0.
A.8.0.1.
Symbol Conversion
General Symbols
Annex 8
Annex 7
Unit
Quantity
b, D
a
t.b.d.
γ intercept of the regression line
m
a
t.b.d.
Slope of the regression line
A/F

Stoichiometric air to fuel ratio
C
C

Discharge coefficient
c
x
ppm, % vol
Concentration (μmol/mol = ppm)
c
ppm, % vol
Concentration on dry basis
c
ppm, % vol
Concentration on wet basis
c
ppm, % vol
Background concentration
D
x

Dilution factor
D
m /rev
PDP calibration intercept
d
d
m
Diameter
d
m
Throat diameter of venture
e
e
g/kWh
Brake specific basis
e
e
g/kWh
Specific emission of gaseous components
e
e
g/kWh
Specific emission of particulates
E
1 – PF
%
Conversion efficiency (PF = Penetration fraction)
F

Stoichiometric factor
ƒ

Carbon factor
H
g/kg
Absolute humidity
K
⎡⎛
⎞ ⎤ CFV calibration function
⎢⎜
K ⋅ m ⋅ s ⎟ / kg⎥
⎣⎝
⎠ ⎦
k
m /kg fuel
Fuel specific factor
k

Humidity correction factor for NO , diesel engines
k
k

Downward adjustment factor
k
k

Multiplicative regeneration factor
k
k

Upward adjustment factor
k

Dry to wet correction factor for the intake air
k

Dry to wet correction factor for the dilution air
k

Dry to wet correction factor for the diluted exhaust
gas
k

Dry to wet correction factor for the raw exhaust
gas
μ
μ
kg/(m·s)
Dynamic viscosity
M
M
g/mol
Molar mass

Annex 8
Annex 7
Unit
Quantity
q
kg/s
Equivalent diluted exhaust gas mass flow rate on wet
basis
q
kg/s
Exhaust gas mass flow rate on wet basis
q
kg/s
Sample mass flow rate extracted from dilution tunnel
q
kg/s
Fuel mass flow rate
q
kg/s
Sample flow of exhaust gas into partial flow dilution
system
q
V
m /s
Volume flow rate
q
m /s
CVS volume rate
q
dm /min
System flow rate of exhaust analyzer system
q
cm /min
Tracer gas flow rate
ρ
ρ
kg/m
Mass density
ρ
kg/m
Exhaust gas density
r
DR

Dilution ratio
RH
%
Relative humidity
r
β
m/m
Ratio of diameters (CVS systems)
r

Pressure ratio of SSV
Re
Re

Reynolds number
σ
σ

Standard deviation
T
T
°C
Temperature
T
K
Absolute temperature
t
t
s
Time
Δt
Δt
s
Time interval
u

Ratio between densities of gas component and exhaust
gas
V
V
m
Volume
q
V
m /s
Volume rate
V
m /r
PDP gas volume pumped per revolution
W
W
kWh
Work
W
W
kWh
Actual cycle work of the test cycle
WF
WF

Weighting factor
w
w
g/g
Mass fraction
X
γ
K
γ
s/rev
PDP calibration function
Arithmetic mean
(1) See subscripts; e.g.: m for mass rate of dry air, m for fuel mass rate, etc.
(2) Dilution ratio r in Annex 8 and DR in Annex 7: different symbols but same meaning and same
equations. Dilution factor D in Annex 8 and x in Annex 7: different symbols but same
physical meaning; equation (A.7-47) shows the relationship between x and DR.
(3) t.b.d.= to be defined

A.8.0.4.
Symbols and Abbreviations for the Fuel Composition
Annex 8
Annex 7
Quantity
w
w
Carbon content of fuel, mass fraction [g/g] or [% mass]
w
w
Hydrogen content of fuel, mass fraction [g/g] or [% mass]
w
w
Nitrogen content of fuel, mass fraction [g/g] or [% mass]
w
w
Oxygen content of fuel, mass fraction [g/g] or [% mass]
w
w
Sulphur content of fuel, mass fraction [g/g] or [% mass]
a
a
Atomic hydrogen-to-carbon ratio (H/C)
ε
β
Atomic oxygen-to-carbon ratio (O/C)
γ
γ
Atomic sulphur-to-carbon ratio (S/C)
δ
δ
Atomic nitrogen-to-carbon ratio (N/C)
Referred to a fuel with chemical formula CHaOεN S
(2) Referred to a fuel with chemical formula CHaO S N
(3) Attention should be paid to the different meaning of symbol β in the two emissions
calculation annexes: in Annex 8 it refers to a fuel having the chemical formula
CHaS N O (i.e. the formula C HaS N O where β = 1, assuming one carbon atom per
molecule), while in Annex 7 it refers to the oxygen-to-carbon ratio with CHaO S N .
Then β of Annex 7 corresponds to ε of Annex 8.
(4) Mass fraction w accompanied by the symbol of the chemical component as a
subscript.
A.8.1.
A.8.1.1.
Basic Parameters
Determination of Methane and Non-Methane HC Concentration
The calculation of NMHC and CH depends on the calibration method used. The FID
for the measurement without NMC, shall be calibrated with propane. For the
calibration of the FID in series with NMC, the following methods are permitted.
(a)
(b)
calibration gas – propane; propane bypasses NMC,
calibration gas – methane; methane passes through NMC
The concentration of NMHC (c
[-]) and CH (c
[-]) shall be calculated as
follows for (a):
C
C
⋅ ( 1 − E ) −
( E − E )
C
C
= (A.8-1a)
⋅ ( 1 − E )
( E − E )
C − C
= (A.8-2a)
RF


A.8.2.1.2.
Transient and Ramped Modal Cycles Tests
The total mass per test of a gaseous emission m [g/test] shall be calculated by
multiplication of the time aligned instantaneous concentrations and exhaust gas flows
and integration over the test cycle according to the following equation:
m
( q ⋅ )
= 1 ⋅ k ⋅ k ⋅ u ⋅ ∑ C
ƒ
(A.8-4)
Where:
ƒ = data sampling rate [Hz]
k = NO correction factor [-], only to be applied for the NO emission
calculation
k = 1 for c in [ppm] and k = 10,000 for c in [% vol]
u = component specific factor [-] (see Paragraph A.8.2.4.)
N = number of measurements [-]
q = instantaneous exhaust gas mass flow rate on a wet basis [kg/s]
c
=
instantaneous emission concentration in the raw exhaust gas, on a wet
basis [ppm] or [% vol]
The following chapters show how the needed quantities (c
, u
and q
) shall be
calculated.
A.8.2.2.
Dry-to-Wet Concentration Conversion
If the emissions are measured on a dry basis, the measured concentration c on dry
basis shall be converted to the concentration c on a wet basis according to the
following general equation:
c = k ⋅ c
(A.8-5)
Where:
k = dry-to-wet conversion factor [-]
c = emission concentration on a dry basis [ppm] or [% vol]

In the equation (A.8-6), the ratio P /P may be assumed:
1
= 1.008
(A.8-8)
⎛ P ⎞
⎜1
− ⎟
⎝ P ⎠
For incomplete combustion (rich fuel air mixtures) and also for emission tests without
direct air flow measurements, a second method of k calculation is preferred:
k
1
1 + a ⋅ 0.005 ⋅
=
P
1 -
P
( C + C )
− k
(A.8-9)
Where:
c
=
concentration of CO in the raw exhaust gas, on a dry basis [% vol]
c
=
concentration of CO in the raw exhaust gas, on a dry basis [ppm]
p
=
water pressure after cooler [kPa] (see equation (A.8-9))
p
=
total barometric pressure [kPa] (see equation (A.8-9))
a
=
molar to carbon hydrogen ratio [-]
k
=
intake air moisture [-]
k
1.608 ⋅ H
= (A.8-10)
1000 + 1.608 ⋅ H
A.8.2.3.
NO Correction for Humidity and Temperature
As the NO emission depends on ambient air conditions, the NO concentration shall
be corrected for ambient air temperature and humidity with the factors k [-] given
in the following equation. This factor is valid for a humidity range between 0 and
25 g /kg dry air.
Where:
15.698 ⋅ H
k =
+ 0.832
(A.8-11)
1000
H = humidity of the intake air [g H O/kg dry air]

The molar mass of the exhaust, M shall be derived for a general fuel composition
CH O N S under the assumption of complete combustion, as follows:
M
=
q
q
q
1 +
q
a ε δ
+ +

4 2 2
12.001 + 1.00794 ⋅ a + 15.9994 ⋅ ε + 14.0067 ⋅ δ + 32.0065 ⋅ γ
+
H ⋅ 10
1
+
2 × 1.00794 + 15.9994 M
1 + H ⋅ 10
(A.8-14)
Where:
q
=
instantaneous fuel mass flow rate on wet basis [kg/s]
q
=
instantaneous intake air mass flow rate on wet basis [kg/s]
a
=
molar hydrogen-to-carbon ratio [-]
δ
=
molar nitrogen-to-carbon ratio [-]
ε
=
molar oxygen-to-carbon ratio [-]
γ
=
atomic sulphur-to-carbon ratio [-]
H
=
intake air humidity [g H2O/kg dry air]
M
=
dry intake air molecular mass = 28.965 g/mol
The instantaneous raw exhaust density P [kg/m ] shall be derived as follows:
p
Where:
( q / q )
⋅ ( q / q )
1000 + H + 1000 ⋅
= (A.8-15)
773.4 + 1.2434 ⋅ H + k ⋅ 1000
q
=
instantaneous fuel mass flow rate [kg/s]
q
=
instantaneous dry intake air mass flow rate [kg/s]
H
=
intake air humidity [g H2O/kg dry air]
k
=
combustion additional volume [m3/kg fuel] (see equation A.8-7)

with:
A/F
⎛ a ε ⎞
138.0 ⋅ ⎜1
+ − + γ ⎟
⎝ 4 2 ⎠
=
12.011 + 1.00794 ⋅ a + 15.9994 ⋅ ε + 14.0067 ⋅ δ + 32.065 ⋅ γ
(A.8-19)
⎛ 2 ⋅ c ⋅ 10



⎛ c ⋅ 10
⎞ ⎜ a 3.5 ⋅ c

⎜100
10 ⎟
ε δ

− c ⋅ + ⎜ ⋅
− − ⎟ ⋅ ( c + c ⋅ 10 )
2

⎠ ⎜
4 c ⋅ 10 2 2
1

+
3.5

⋅ c

λ =
(A.8-20)
⎛ a ε ⎞
4.764 ⋅ ⎜1
+ − + γ ⎟ ⋅ ( c + c ⋅ 10 + c ⋅ 10 )
⎝ 4 2 ⎠
Where:
q
=
wet intake air mass flow rate [kg/s]
A/F =
stoichiometric air-to-fuel ratio [-]
λ
=
instantaneous excess air ratio [-]
c
=
concentration of CO in the raw exhaust gas on a dry basis [ppm]
c
=
concentration of CO in the raw exhaust gas on a dry basis [%]
c
=
concentration of HC in the raw exhaust gas on a wet basis [ppm C1]
a
=
molar hydrogen-to-carbon ratio [-]
δ
=
molar nitrogen-to-carbon ratio [-]
ε
=
molar oxygen-to-carbon ratio [-]
γ
=
atomic sulphur-to-carbon ratio [-]

A.8.3.
A.8.3.1.
A.8.3.1.1.
Diluted Gaseous Emissions
Mass of the Gaseous Emissions
Full Flow Dilution Measurement (CVS)
The exhaust mass flow rate shall be measured with a constant volume sampling
(CVS) system, which may use a positive displacement pump (PDP), a critical flow
venturi (CFV) or a subsonic venturi (SSV).
For systems with constant mass flow (i.e. with heat exchanger), the mass of the
pollutants m [g/test] shall be determined from the following equation:
Where:
m = k ⋅ k ⋅ u ⋅ c ⋅ m (A.8-24)
u
=
ratio between density of exhaust component and density of air, as given in
Table A.8.2 or calculated with equation (A.8-35) [-]
c
=
mean background corrected concentration of the component on a wet
basis [ppm] or [% vol] respectively
k
=
NO correction factor [-], only to be applied for the NO emission
calculation
k = 1 for c in [ppm], k = 10,000 for c in [% vol]
m = total diluted exhaust gas mass over the cycle [kg/test]
For systems with flow compensation (without heat exchanger), the mass of the
pollutants m [g/test] shall be determined by calculation of the instantaneous mass
emissions, by integration and by background correction according to the following
equation:
[( m ⋅ c ⋅ u )]
⎧ ⎡⎛
⎛ 1 ⎞ ⎞⎤⎫
m = k ⋅ k ⋅ ⎨ ∑
− ⎢⎜m
⋅ c ⋅ ⎜1 − ⎟ ⋅ u ⎟⎥⎬
(A.8-25)

⎣⎝
⎝ D ⎠ ⎠ ⎦ ⎭
Where:
c
=
emission concentration in the diluted exhaust gas, on a wet basis [ppm] or
[% vol]
c = emission concentration in the dilution air, on a wet basis [ppm] or [% vol]
m = mass of the diluted exhaust gas during time interval i [kg]
m = total mass of diluted exhaust gas over the cycle [kg]
u = tabulated value from Table A.8.2 [-]
D = dilution factor (see equation (A.8-29) of Paragraph A.8.3.2.2.) [-]
k
=
NO correction factor [-], only to be applied for the NO emission
calculation
k = 1 for c in [ppm], k = 10,000 for c in [% vol]

The dry to wet correction factor k takes into consideration the water content of both
intake air and dilution air:
k

⎞ ⎛ ⎞⎤
⎢ ⎜
⎛ 1 1
1.608 ⋅ H ⋅ 1 − ⎟ + H ⋅ ⎜ ⎟⎥ ⎣ ⎝ D ⎠ ⎝ D ⎠
=

⎧ ⎡ ⎛ 1 ⎞ ⎛ 1 ⎞⎤⎫
1000 + ⎨1.608
⋅ ⎢H
⋅ ⎜1
− ⎟ + H ⋅ ⎜ ⎟⎥⎬
⎩ ⎣ ⎝ D ⎠ ⎝ D ⎠⎦⎭
(A.8-28)
Where:
H
=
intake air humidity [g H O/kg dry air]
H
=
dilution air humidity [g H O/kg dry air]
D
=
dilution factor (see equation (A.8-29) of Paragraph A.8.3.2.2.) [-]
A.8.3.2.2.
Dilution Factor
The dilution factor D [-] (which is necessary for the background correction and the k
calculation) shall be calculated as follows:
Where:
F
D =
(A.8-29)
c +
F = stoichiometric factor [-]
( c + c ) ⋅ 10
c = concentration of CO in the diluted exhaust gas on a wet basis [% vol]
c = concentration of HC in the diluted exhaust gas on a wet basis [ppm C1]
c = concentration of CO in the diluted exhaust gas on a wet basis [ppm]
The stoichiometric factor shall be calculated as follows:
Where:
F 1
= 100 ⋅
a


⎛ a
(A.8-30)
1 + + 3.76 ⋅ 1 + ⎟
2 ⎝ 4 ⎠
a = molar hydrogen to carbon ratio in the fuel [-]
Alternatively, if the fuel composition is not known, the following stoichiometric factors
may be used: F (diesel) = 13.4

A.8.3.3.
Component Specific Factor u
The component specific factor u of diluted gas can either be calculated by the
following equation or be taken from Table A.8.2; in Table A.8.2 the density of the
diluted exhaust gas has been assumed equal to air density.
Where:
M
M
u =
=
(A.8-35)
M ⋅ 1000 ⎡ ⎛ 1 ⎞ ⎛ 1 ⎞⎤
⎢M
⋅ ⎜1
− ⎟ + M ⋅ ⎜ ⎟⎥
⋅ 1000
⎣ ⎝ D ⎠ ⎝ D ⎠⎦
M = molar mass of the gas component [g/mol]
M = molar mass of diluted exhaust gas [g/mol]
M = molar mass of dilution air [g/mol]
M = molar mass of raw exhaust gas [g/mol]
D = dilution factor (see equation (A.8-29) of Paragraph A.8.3.2.2.) [-]
Table A.8.2
Diluted Exhaust Gas u Values and Component Densities (the u Figures
are Calculated for Emission Concentration Expressed in ppm)
Gas NO CO HC CO O CH
P [kg/m ] 2.053 1.250 0.621 1.9636 1.4277 0.716
Fuel
P
[kg/m ]
Coefficient u at λ = 2, dry air, 273 K, 101.3 kPa
Diesel 1.293 0.001588 0.000967 0.000480 0.001519 0.001104 0.000553

A.8.3.4.2.
CFV-CVS System
The calculation of the mass flow over the cycle m [g/test] is as follows, if the
temperature of the diluted exhaust is kept within ± 11 K over the cycle by using a heat
exchanger:
m
1.293 ⋅ t ⋅ K ⋅ P
= (A.8-38)
T
Where:
t = cycle time [s]
K
=
calibration coefficient of the critical flow venturi for standard
conditions


⎛ K ⋅ m ⋅ s⎟
⎞ / kg

⎢⎣ ⎝ ⎠ ⎥⎦
p = absolute pressure at venturi inlet [kPa]
T = absolute temperature at venturi inlet [K]
1.293 kg/m = air density at 273.15 K and 101.325 kPa
If a system with flow compensation is used (i.e. without heat exchanger), the mass of
the diluted exhaust gas m [kg] during the time interval shall be calculated as
follows:
m
1.293
⋅ Δt
⋅ K ⋅ P
= (A.8-39)
T
Where:
Δt = time interval of the test [s]
K
=
calibration coefficient of the critical flow venturi for standard
conditions


⎛ K ⋅ m ⋅ s⎟
⎞ / kg

⎢⎣ ⎝
⎠ ⎥⎦
p = absolute pressure at venturi inlet [kPa]
T = absolute temperature at venturi inlet [K]
1.293 kg/m = air density at 273.15 K and 101.325 kPa

If a system with flow compensation is used (i.e. without heat exchanger), the mass
of the diluted exhaust gas m [kg] during the time interval shall be calculated as
follows:
Where:
m = 1.293 ⋅ q ⋅ Δt (A.8-42)
1.293 kg/m = air density at 273.15 K and 101.325 kPa
Δt = time interval [s]
q = volumetric flow rate of the SSV [m /s]
A.8.3.5.
A.8.3.5.1.
Calculation of Particulates Emission
Transient and Ramped Modal Cycles
The particulate mass shall be calculated after buoyancy correction of the
particulate sample mass according to Paragraph 8.1.12.2.5.
A.8.3.5.1.1.
Partial flow dilution system
The calculation for double dilution system is shown in Paragraph A.8.3.5.1.2.
A.8.3.5.1.1.1.
Calculation based on sample ratio
The particulate emission over the cycle m [g] shall be calculated with the
following equation:
Where:
m
m = (A.8-43)
r ⋅ 1000
m = particulate mass sampled over the cycle [mg]
r = average sample ratio over the test cycle [-]
with:
r
m m
= ⋅
(A.8-44)
m m
Where:
m
= sample mass of raw exhaust over the cycle [kg]
m
= total mass of raw exhaust over the cycle [kg]
m
= mass of diluted exhaust gas passing the particulate collection filters [kg]
m
= mass of diluted exhaust gas passing the dilution tunnel [kg]
In case of the total sampling type system, m
and m
are identical.

A.8.3.5.1.2.
Full flow dilution system
The mass emission shall be calculated as follows:
m
m m
= ⋅
(A.8-49)
m 1000
Where:
m
= particulate mass sampled over the cycle [mg]
m = mass of diluted exhaust gas passing the particulate collection filters [kg]
m
= mass of diluted exhaust gas over the cycle [kg]
with
m
= m − m
(A.8-50)
Where:
m = mass of double diluted exhaust gas through particulate filter [kg]
m = mass of secondary dilution air [kg]
A.8.3.5.1.3.
Background correction
The particulate mass m [g] may be background corrected as follows:
m
⎪⎧
m ⎡ m ⎛ 1 ⎞⎤⎪⎫
m
= ⎨ − ⎢ ⋅ ⎜1
− ⎟⎥⎬

(A.8-51)
⎪⎩ m ⎣m
⎝ D ⎠⎦⎪⎭
1000
Where:
m
= particulate mass sampled over the cycle [mg]
m = mass of diluted exhaust gas passing the particulate collection filters [kg]
m
m
m
= mass of dilution air sampled by background particulate sampler [kg]
= mass of collected background particulates of dilution air [mg]
= mass of diluted exhaust gas over the cycle [kg]
D = dilution factor (see equation (A.8-29) of Paragraph A.8.3.2.2.) [-]

m = ∑ m
(A.8-56)
Where:
q = particulate mass flow rate [g/h]
m
= particulate mass sampled over the cycle [mg]
q = average equivalent diluted exhaust gas mass flow rate on wet basis
[kg/s]
q = equivalent diluted exhaust gas mass flow rate on wet basis at mode i
[kg/s]
WF = weighting factor for the mode i [-]
m = mass of diluted exhaust gas passing the particulate collection filters [kg]
m = mass of diluted exhaust sample passed through the particulate sampling
filter at mode i [kg]
N = number of measurements [-]
(b)
For the multiple-filter method
m
3600
q = ⋅ q ⋅
(A.8-57)
m
1000
Where:
q = particulate mass flow rate for the mode i [g/h]
m
= particulate sample mass collected at mode i [mg]
q = equivalent diluted exhaust gas mass flow rate on wet basis at mode i
[kg/s]
m = mass of diluted exhaust sample passed through the particulate sampling
filter at mode i [kg]
The PM mass is determined over the test cycle by summation of the average
values of the individual modes i during the sampling period.

(d)
For the multiple-filter method
q
⎪⎧
m ⎡m
⎛ 1 ⎞⎤⎪⎫
3600
= ⎨ − ⎢ ⋅ ⎜1 − ⎟⎥⎬
⋅ q
(A.8-59)
⎪⎩
m ⎣ m ⎝ D ⎠⎦⎪⎭
1000
Where:
q = particulate mass flow rate at mode i [g/h]
m = particulate sample mass collected at mode i [mg]
m
=
mass of diluted exhaust sample passed through the particulate
sampling filter at mode i [kg]
m = particulate sample mass of the dilution air collected [mg]
m
=
mass of the dilution air sample passed through the particulate
sampling filters [kg]
D = dilution factor (see equation (A.8-29) of Paragraph A.8.3.2.2.) [-]
q
=
equivalent diluted exhaust gas mass flow rate on wet basis at mode
i [kg/s]
If more than one measurement is made, m /m shall be replaced with
m / m .

A.8.4.1.2.
Steady-State Discrete-Mode Cycle
The specific emissions e [g/kWh] are calculated as follows:

( q ⋅ WF )

e =
(A.8-63)
( P ⋅ WF
)
Where:
q = mean emission mass flow rate for the mode i [g/h]
P
=
engine power for the mode i [kW] with P = P
+ P
(see
Paragraphs 7.7.1.2. and 6.3.)
WF = weighting factor for the mode i [-]
A.8.4.2.
A.8.4.2.1.
Particulate Emissions
Transient and Ramped Modal Cycles
The particulate specific emissions shall be calculated with equation (A.8-61) where
e [g/kWh] and m [g/test] are substituted by e [g/kWh] and m [g/test]
respectively:
Where:
m
e = (A.8-64)
W
m
=
total mass of particulates emission, calculated according to
Paragraph A.8.3.5. [g/test]
W = cycle work [kWh]
The emissions on the transient composite cycle (i.e. cold phase and hot phase)
shall be calculated as shown in Paragraph A.8.4.1.

For the single-filter method, the effective weighting factor, WF , for each mode
shall be calculated in the following way:
WF
m ⋅ q
= (A.8-67)
m ⋅ q
Where:
m = mass of the diluted exhaust sample passed through the particulate
sampling filters at mode i [kg]
q = average equivalent diluted exhaust gas mass flow rate [kg/s]
q = equivalent diluted exhaust gas mass flow rate at mode i [kg/s]
m = mass of the diluted exhaust sample passed through the particulate
sampling filters [kg]
The value of the effective weighting factors shall be within ± 0.005 (absolute value)
of the weighting factors listed in Annex A.1.

To account for the interaction of pressure variations at the pump and the pump slip
rate, the correlation function (X ) [s/rev] between pump speed, pressure differential
from pump inlet to pump outlet and absolute pump outlet pressure shall be
calculated as follows:
X
1 ΔP
= ⋅
(A.8-69)
n P
Where:
Δp = pressure differential from pump inlet to pump outlet [kPa]
p = absolute outlet pressure at pump outlet [kPa]
n = pump speed [rev/s]
A linear least-square fit shall be performed to generate the calibration equation as
follows:
V = D - m ⋅ X
(A.8-70)
with D [m /rev] and m [m /s], intercept and slope respectively, describing the
regression line.
For a CVS system with multiple speeds, the calibration curves generated for the
different pump flow ranges shall be approximately parallel, and the intercept
values (D ) shall increase as the pump flow range decreases.
The calculated values from the equation shall be within ± 0.5% of the measured
value of V . Values of m will vary from one pump to another. Particulate influx
over time will cause the pump slip to decrease, as reflected by lower values for m.
Therefore, calibration shall be performed at pump start-up, after major
maintenance, and if the total system verification indicates a change of the slip rate.
A.8.5.2.
Critical Flow Venturi (CFV)
Calibration of the CFV is based upon the flow equation for a critical venturi. Gas
flow is a function of venturi inlet pressure and temperature. To determine the
range of critical flow, K shall be plotted as a function of venture inlet pressure.
For critical (choked) flow, K will have a relatively constant value. As pressure
decreases (vacuum increases), the venturi becomes unchoked and K decreases,
which indicates that the CFV is operated outside the permissible range.
The airflow rate (q ) at each restriction setting (minimum 8 settings) shall be
calculated in standard m /s from the flowmeter data using the manufacturer's
prescribed method. The calibration coefficient K


⎛ K ⋅ m ⋅ s⎟
⎞ / kg

shall be
⎢⎣ ⎝ ⎠ ⎥⎦
calculated from the calibration data for each setting as follows:

To determine the range of subsonic flow, C shall be plotted as a function of Reynolds
number Re, at the SSV throat. The Re at the SSV throat shall be calculated with the
following equation:
with
Where:
q
Re = A ⋅ 60 ⋅
(A.8-73)
d ⋅ μ
b × T
μ = (A.8-74)
S + T
⎡ Kg min mm⎤
A = collection of constants and units conversions = 27.43831 ⎢ ⋅ ⋅ ⎥
⎣m
s m ⎦
q = air flow rate at standard conditions (101.325 kPa, 273.15 K) [m /s]
d
μ
= diameter of the SSV throat [mm]
= absolute or dynamic viscosity of the gas [kg/m·s]
b = 1.458 x 10 (empirical constant) [kg/m·s·K ]
S
= 110.4 (empirical constant) [K]
Because q is an input to the Re equation, the calculations shall be started with an
initial guess for q or C of the calibration venturi, and repeated until q
converges. The convergence method shall be accurate to 0.1% of point or better.
For a minimum of sixteen points in the region of subsonic flow, the calculated values
of C from the resulting calibration curve fit equation shall be within ± 0.5% of the
measured C for each calibration point.

Agricultural and Forestry Tractors and Non-road Mobile Machinery Engine Emissions.