Regulation No. 138-01

Name:Regulation No. 138-01
Description:Regulation on the Approval of Quiet Road Transport Vehicles (QRTV).
Official Title:Uniform Provisions Concerning the Approval of Quiet Road Transport Vehicles with Regard to their Reduced Audibility.
Country:ECE - United Nations
Date of Issue:2017-11-16
Amendment Level:01 Series, Supplement 2
Number of Pages:42
Vehicle Types:Bus, Car, Component, Heavy Truck, Light Truck
Subject Categories:Electrical and Electronic, Noise
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Keywords:

vehicle, test, sound, speed, approval, regulation, annex, level, paragraph, type, frequency, measurement, background, noise, pressure, avas, condition, vehicles, manufacturer, facility, reported, constant, requirements, a-weighted, conditions, line, measurements, range, means, figure, appendix, series, microphone, indoor, amendments, maximum, outdoor, granted, tests, shift, tested, minimum, target, plane, engine, specifications, simulated, method, motion, date

Text Extract:

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E/ECE/324
) Rev.2/Add.137/Rev.1/Amend.2
E/ECE/TRANS/505 )
February 2, 2021
STATUS OF UNITED NATIONS REGULATION
ECE 138-01
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF:
QUIET ROAD TRANSPORT VEHICLES WITH REGARD
TO THEIR REDUCED AUDIBILITY (QRTV)
Incorporating:
00 series of amendments
Date of Entry into Force: 05.10.16
Supplement 1 to the 00 series of amendments
Date of Entry into Force: 10.10.17
01 series of amendments
Date of Entry into Force: 10.10.17
Supplement 1 to the 01 series of amendments
Date of Entry into Force: 11.01.20
Supplement 2 to the 01 series of amendments
Date of Entry into Force: 03.01.21

REGULATION
1. Scope
UN REGULATION No. 138-01
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF QUIET ROAD
TRANSPORT VEHICLES WITH REGARD TO THEIR REDUCED AUDIBILITY (QRTV)
2. Definitions
3. Application for approval
4. Markings
5. Approval
6. Specifications
CONTENTS
7. Modification and extension of approval of a vehicle type
8. Conformity of production
9. Penalties for non-conformity of production
10. Production definitively discontinued
11. Transitional provisions
12. Names and addresses of Technical Services responsible for conducting approval tests, and of
Type Approval Authorities
Annexes
Annex 1
Communication
Addendum to the Communication Form (Technical Information document)
Annex 2
Annex 3
Arrangements of the approval mark
Methods and instruments for measuring the sound made by motor vehicles
Appendix: Figures and Flowcharts

2.5.2. "Hybrid Electric Vehicle" (HEV) means a vehicle with a powertrain containing at least one
electric motor or electric motor generator and at least one internal combustion engine as
propulsion energy converters.
2.5.3. "Fuel Cell vehicle" (FCV) means a vehicle with a fuel cell and an electric machine as
propulsion energy converters.
2.5.4. "Fuel Cell Hybrid Vehicle" (FCHV) means a vehicle with at least one fuel storage system
and at least one Rechargeable Electric Energy Storage System (REESS) as propulsion
energy storage system.
2.6. "Mass in running order" means the mass of the vehicle, with its fuel tank(s) filled to at
least 90% of its or their capacity/ies, including the mass of the driver (75kg), of the fuel and
liquids, fitted with the standard equipment in accordance with the manufacturer’s
specifications and, when they are fitted, the mass of the bodywork, the cabin, the coupling
and the spare wheel(s) as well as the tools.
2.7. "Pause function" means a mechanism to enable the driver to halt the operation of an
AVAS.
2.8. "Front plane of the vehicle" means a vertical plane tangent to the leading edge of the
vehicle.
2.9. "Rear plane of the vehicle" means a vertical plane tangent to the trailing edge of the
vehicle.
2.10. Symbols and abbreviated terms and the paragraph in which they are first used.

3. APPLICATION FOR APPROVAL
3.1. The application for approval of a vehicle type with regard to reduced audibility shall be
submitted by its manufacturer or by a duly accredited representative.
3.2. It shall be accompanied by the undermentioned documents and the following particulars:
3.2.1. A description of the vehicle type with regard to the items mentioned in Paragraph 2.3.
above;
3.2.2. A description of the engine(s) as mentioned in Annex 1, Addendum;
3.2.3. If applicable, a list of the components constituting the AVAS;
3.2.4. If applicable, a drawing of the assembled AVAS and an indication of its position on the
vehicle.
3.3. In the case of Paragraph 2.3., the single vehicle, representative of the type in question, will
be selected by the Technical Service conducting approval tests, in accordance with the
vehicle manufacturer.
3.4. The Type Approval Authority shall verify the existence of satisfactory arrangements for
ensuring effective control of the conformity of production before type approval is granted.
4. MARKINGS
4.1. The components of the AVAS (if applicable) shall bear:
4.1.1. The trade name or mark of the manufacturer(s) of the AVAS components;
4.1.2. A designated identification number(s).
4.2. These markings shall be clearly legible and be indelible.
5. APPROVAL
5.1. Type approval shall only be granted if the vehicle type meets the requirements of
Paragraphs 6 and 7 below.
5.1.1. In case of hybrid vehicles, equipped with an internal combustion engine: if the manufacturer
can demonstrate to the Type Approval Authority that the vehicle cannot be assessed
according to the provisions of the Regulation because the internal combustion engine used
for direct propulsion will be operational during the specified tests within this Regulation, this
Regulation shall be deemed not applicable to this vehicle.
5.2. An approval number shall be assigned to each type approved. Its first two digits (at present
00 corresponding to the 00 series of amendments) shall indicate the series of amendments
incorporating the most recent major technical amendments made to the Regulation at the
time of issue of the approval. The same Contracting Party shall not assign the same number
to another vehicle type.
5.3. Notice of approval or of extension or of refusal or withdrawal of approval or of production
definitively discontinued of a vehicle type pursuant to this Regulation shall be communicated
to the Parties to the Agreement applying this Regulation by means of a form conforming to
the model in Annex 1 to this Regulation.

(b)
(c)
That has at least two of the one-third octave bands according to Table 2 of
Paragraph 6.2.8. At least one of these bands shall be below or within the 1,600Hz
one-third octave band;
With minimum sound pressure levels in the chosen bands for the applicable test
speed according to Table 2 of Paragraph 6.2.8., Column 3 or Column 4.
6.2.1.3. If after a vehicle is tested in accordance with Annex 3 Paragraph 3.3.2., for ten consecutive
times within a series of measurements without recording a valid measurement because the
vehicle’s internal combustion engine (ICE) remains active or restarts and interferes with the
measurements, the vehicle is exempted from this particular test.
6.2.2. Reversing Test
6.2.2.1. When tested under the conditions of Annex 3 Paragraph 3.3.3. the vehicle must emit a
sound that has a minimum overall sound pressure level according to Table 2 of
Paragraph 6.2.8., Column 5.
6.2.2.2. If after a vehicle is tested in accordance with Annex 3, Paragraph 3.3.3., for ten consecutive
times within a series of measurements without recording a valid measurement because the
vehicle’s ICE remains active or restarts and interferes with the measurements, the vehicle is
exempted from this particular test.
6.2.3. Frequency Shift to Signify Acceleration and Deceleration
6.2.3.1. The intention of frequency shift is to acoustically inform road users about the change in
vehicle speed.
6.2.3.2. When tested under the conditions of Annex 3 Paragraph 4, at least one tone within the
frequency range as specified in Paragraph 6.2.8. emitted by the vehicle shall vary
proportionally with speed within each individual gear ratio by an average of at least 0.8% per
1km/h in the speed range from 5km/h to 20km/h inclusive when driving in forward direction.
In case more than one frequency is shifted, only one frequency shift needs to fulfil the
requirements.
6.2.4. Stationary Sound
The vehicle may emit a sound when stationary.
6.2.5. Driver Selectable Sounds
The vehicle manufacturer may define alternative sounds which can be selected by the
driver; each of these sounds shall be in compliance and approved with the provisions in
Paragraphs 6.2.1. to 6.2.3.
6.2.6. AVAS Sound Level Variation
If fitted, an AVAS may operate at different sound levels either automatically managed by the
control unit or manually selected by the driver, each selected sound level shall be in
compliance with the specifications outlined in Paragraphs 6.2.1. to 6.2.3. and
Paragraphs 6.2.8. and 6.2.9.

7. MODIFICATION AND EXTENSION OF APPROVAL OF A VEHICLE TYPE
7.1. Every modification of the vehicle type shall be notified to the Type Approval Authority which
approved the vehicle type. The Type Approval Authority may then either:
7.1.1. Consider that the modifications made are unlikely to have an appreciable adverse effect and
that in any case the vehicle still complies with the requirements, or
7.1.2. Require a further test report from the Technical Service responsible for conducting the tests.
7.2. Confirmation or refusal of approval, specifying the alterations shall be communicated by the
procedure specified in Paragraph 5.3. above to the Parties to the Agreement applying this
Regulation.
7.3. The Type Approval Authority issuing the extension of approval shall assign a series number
for such an extension and inform thereof the other Parties to the 1958 Agreement applying
this Regulation by means of a communication form conforming to the model in Annex 1 to
this Regulation.
8. CONFORMITY OF PRODUCTION
The conformity of production procedures shall comply with those set out in the Agreement,
Appendix 2 (E/ECE/324-E/ECE/TRANS/505/Rev.2) with the following requirements:
8.1. Vehicles approved according to this Regulation shall be manufactured so as to conform to
the type approved and satisfy the requirements set forth in Paragraph 6.2. above.
8.2. The authority which has granted type approval may at any time verify the conformity control
methods applied in each production facility. The normal frequency of these verifications
shall be one every two years.
9. PENALTIES FOR NON-CONFORMITY OF PRODUCTION
9.1. The approval granted in respect of a vehicle type pursuant to this Regulation may be
withdrawn if the requirements set forth above are not met.
9.2. If a Contracting Party to the Agreement applying this Regulation withdraws an approval it
has previously granted, it shall forthwith so notify the other Contracting Parties applying this
Regulation, by means of a communication form conforming to the model in Annex 1 to this
Regulation.
10. PRODUCTION DEFINITIVELY DISCONTINUED
If the holder of the approval completely ceases to manufacture a vehicle type approved in
accordance with this Regulation, he shall so inform the authority which granted the
approval. Upon receiving the relevant communication that authority shall inform thereof the
other Parties to the 1958 Agreement applying this Regulation by means of a communication
form conforming to the model in Annex 1 to this Regulation.

ANNEX 1
COMMUNICATION
(Maximum format: A4 (210 × 297mm))
Issued by:
Name of administration
.....................................
.....................................
.....................................
Concerning:
Approval granted
Approval extended
Approval refused
Approval withdrawn
Production definitively discontinued
of a vehicle type with regard to its sound emission pursuant to Regulation No. 138
Approval No.: .......................................................... Extension No.: ....................................................
SECTION I
0.1. Make (trade name of manufacturer): .............................................................................................
0.2. Vehicle type .....................................................................................................................................
0.3. Means of identification of type if marked on the vehicle: ............................................................
0.3.1. Location of that marking: ................................................................................................................
0.4. Category of vehicle ......................................................................................................................
0.5. Propulsion principle (PEV/HEV/FCV/FCHV): .................................................................................
0.6. Company name and address of manufacturer: ..............................................................................
0.7. Names and Address(es) of assembly plant(s): ..............................................................................
0.8. Name and address of the manufacturer's representative (if any): .................................................

Addendum to the Communication Form No …
Technical Information
0.
General
0.1.
Make (trade name of manufacturer):
0.2.
Means of identification of type, if marked on the vehicle
0.2.1.
Location of that marking:
0.3
Category of vehicle:
0.4.
Company name and address of manufacturer:
0.5.
Name and address of the manufacturer's representative (if any):
0.6.
Name(s) and Address(es) of assembly plant(s):
1.
Additional information
1.1.
Power plant
1.1.1.
Propulsion principle (PEV/HEV/FCV/FCHV):
1.1.2.
Manufacturer of the engine(s):
1.1.3.
Manufacturer's engine code(s):
1.2.
Description of AVAS (if applicable): .............
1.2.1.
Sound at Stationary (yes/no)
1.2.2.
No. of driver selectable sounds (1/2/3/…)
2.
Test results
2.1.
Sound level of moving vehicle: .............. dB(A) at 10km/h
2.2.
Sound level of moving vehicle: .............. dB(A) at 20km/h
2.3.
Sound level of moving vehicle: .............. dB(A) in reversing
2.4.
Frequency shift: .......... % /km/h
3.
Remarks

2.6. Mass in running order
3. Power plant
minimum and maximum: ...........................................................................................................
3.1. Manufacturer of the engine(s):
3.1.1. Manufacturer's engine code(s) (as marked on the engine(s), or other means of
identification): ............................................................................................................................
3.3. Electric motor
3.3.1. Type of the electric motor (winding, excitation):
3.4. Engine or motor combination:
3.4.4. Electric motor (describe each type of electric motor separately)
3.4.4.1. Make: ........................................................................................................................................
3.4.4.2. Type: .........................................................................................................................................
3.4.4.3. Maximum power: ....... kW
6. Suspension
6.6. Tyre size
6.6.2. Upper and lower limits of rolling radii
6.6.2.1. Axle 1: .......................................................................................................................................
6.6.2.2. Axle 2: .......................................................................................................................................
6.6.2.3. Axle 3: .......................................................................................................................................
6.6.2.4. Axle 4: .......................................................................................................................................
etc.
9. Bodywork
9.1. Type of bodywork:
9.2. Materials used and methods of construction:
12. Miscellaneous
12.5. Details of materials and components influencing the sound emission of the vehicle (if not
covered by other items): ...........................................................................................................

ANNEX 2
ARRANGEMENTS OF THE APPROVAL MARKS
Model A
(See Paragraph 5.4. of this Regulation)
a = 8mm min.
The above approval mark affixed to a vehicle shows that the vehicle type concerned has, with regard to
its audibility, been approved in the Netherlands (E 4) pursuant to Regulation No. 138 under approval
No. 002439.
The first two digits of the approval number indicates that Regulation No. 138 already included the
00 series of amendments when the approval was granted.
Model B
(See Paragraph 5.5. of this Regulation)
a = 8mm min.
The above approval mark affixed to a vehicle shows that the vehicle type concerned has been approved
in the Netherlands (E 4) pursuant to Regulations Nos. 138 and 33. The approval numbers indicate that,
at the dates when the respective approvals were granted, Regulation No. 138 included the 00 series of
amendments while Regulation No. 33 included the 01 series of amendments.

1.2. Instrumentation for Speed Measurements
The road speed of the vehicle shall be measured with instruments meeting specification
limits of at least ±0.5km/h when using continuous measuring devices.
If testing uses independent measurements of speed, this instrumentation shall meet
specification limits of at least ±0.2km/h.
1.3. Meteorological Instrumentation
The meteorological instrumentation used to monitor the environmental conditions during the
test shall meet the specifications of:
(a)
(b)
(c)
(d)
±1°C or less for a temperature measuring device;
±1.0m/s for a wind speed-measuring device;
±5hPa for a barometric pressure measuring device;
±5% for a relative humidity measuring device.
2. ACOUSTIC ENVIRONMENT, METEOROLOGICAL CONDITIONS, AND BACKGROUND
NOISE
2.1. Test Site
2.1.1. General
The specifications for the test site provide the necessary acoustic environment to carry out
the vehicle tests documented in this regulation. Outdoor and indoor test environments that
meet the specifications of this regulation provide equivalent acoustic environments and
produce results that are equally valid.
2.1.2. Outdoor Testing
The test site shall be substantially level. For the measurement of vehicles in motion, the test
track construction and surface shall meet the requirements of ISO 10844:2014. For the
measurement of vehicles at a standstill, the test area shall be either:
(a)
(b)
(c)
ISO 10844:2014; or
Other dense asphalt; or
Dense concrete.
Within a radius of 50m around the centre of the track, the space shall be free of large
reflecting objects such as fences, rocks, bridges or buildings. The test track and the surface
of the site shall be dry and free from absorbing materials such as powdery snow, or loose
debris.
In the vicinity of the microphones, there shall be no obstacle that could influence the
acoustic field and no person shall remain between the microphone and the noise source.
The meter observer shall be positioned so as not to influence the meter reading.
Microphones shall be located as specified in Figures 1 of the Appendix to this Annex.

2.2. Meteorological Conditions
2.2.1. For Outdoor Facilities
Meteorological conditions are specified to provide a range of normal operating temperatures
and to prevent abnormal readings due to extreme environmental conditions.
The meteorological instrumentation shall deliver data representative for the test site and
shall be positioned adjacent to the test area at a height representative of the height of the
measuring microphone.
A value representative of temperature, wind speed, relative humidity, and barometric
pressure shall be recorded during the measurement interval.
The measurements shall be made when the ambient air temperature is within the range
from 5°C to 40°C.
The ambient temperature may of necessity be restricted to a narrower temperature range
such that all key vehicle functionalities that can reduce vehicle noise emissions
(e.g. start/stop, hybrid propulsion, battery propulsion, fuel-cell stack operation) are enabled
according to manufacturer's specifications.
The tests shall not be carried out if the wind speed, including gusts, at microphone height
exceeds 5m/s, during the measurement interval.
2.2.2. For Indoor Facilities
Meteorological conditions are specified to provide a range of normal operating temperatures
and to prevent abnormal readings due to extreme environmental conditions.
The meteorological instrumentation shall deliver data representative for the test site and
values of temperature, relative humidity, and barometric pressure shall be recorded during
the measurement interval.
The measurements shall be made when the ambient air temperature is within the range
from 5°C to 40°C.
The ambient temperature may of necessity be restricted to a narrower temperature range
such that all key vehicle functionalities that can reduce vehicle noise emissions
(e.g. start/stop, hybrid propulsion, battery propulsion, fuel-cell stack operation) are enabled
according to manufacturer's specifications.

Range of maximum to minimum
value of the representative
background noise A-weighted
sound pressure level over a defined
time period ∆L in dB(A)
Table 3
Correction for Level of Background Noise when
Measuring Vehicle A-weighted Sound Pressure Level
Correction for background noise
Sound pressure level of
j-th test result minus
background noise level
∆L = L - L
in dB(A)
Correction in dB(A)
L
– ∆L ≥ 10 no correction needed
≤2
8 ≤ ∆L <10 0.5
6 ≤ ∆L <8 1.0
4.5 ≤ ∆L <6 1.5
3 ≤ ∆L <4.5 2.5
∆L <3
no valid measurement can be reported
If a sound peak obviously out of character with the general sound pressure level is
observed, that measurement shall be discarded.
As an aid for measurement correction criteria see flowchart in Figure 5 of the Appendix to
this Annex.
2.3.3. Background Noise Requirements when Analysing in One-third-octave Bands
When analysing one-third octaves according to this regulation, the level of background
noise in each one-third octave of interest, analysed according to Paragraph 2.3.1, shall be
at least 6dB(A) below the measurement of the vehicle or AVAS under test in each
one-third-octave band of interest. The A-weighted sound pressure level of the background
noise shall be at least 10dB(A) below the measurement of the vehicle or AVAS under test.
Background compensation is not permitted for one-third octave band measurements.
As an aid for background noise requirements when analysing in one-third-octave bands see
flowchart in Figure 6 of the Appendix to this Annex.

3.2.4. Test Mass of Vehicle
Measurements shall be made on vehicles at mass in running order with an allowable
tolerance of 15%.
3.2.5. Tyre Selection and Condition
The tyres fitted to the vehicle during testing are selected by the vehicle manufacturer, and
shall correspond to one of the tyre sizes and types designated for the vehicle by the vehicle
manufacturer.
The tyres shall be inflated to the pressure recommended by the vehicle manufacturer for the
test mass of the vehicle.
3.3. Operating Conditions
3.3.1. General
For each operating condition, the vehicle can be tested either indoor or outdoor.
For constant speed and reversing tests the vehicle may be tested either in motion or in
simulated operating condition. For simulated vehicle operation, signals shall be applied to
the vehicle to simulate actual in-use operation.
If the vehicle is equipped with an internal combustion engine, it shall be turned off.
3.3.2. Constant Speed Tests
These tests are conducted with the vehicle in forward motion or with the vehicle speed
simulated by an external signal to the AVAS with the vehicle in standstill condition.
3.3.2.1. Constant Speed Tests in Forward Motion
For a vehicle tested in an outdoor facility, the path of the centreline of the vehicle shall follow
Line CC’ as closely as possible with constant speed v throughout the entire test. The front
plane of the vehicle shall pass from the Line AA’ at the start of the test and the rear plane of
the vehicle shall pass from the Line BB’ at the end of the test, as shown in Figure 1a of the
Appendix to this Annex. Any trailer, which is not readily separable from the towing vehicle,
shall be ignored when considering the crossing of the Line BB’.
A vehicle tested in an indoor facility, shall be located with the front plane of the vehicle on
the PP' Line as shown in Figure 2a of the Appendix to this Annex. The vehicle shall maintain
a constant test speed, v for at least 5s.
For constant speed test condition of 10km/h, the test speed v shall be 10km/h ± 2km/h.
For constant speed test condition of 20km/h, the test speed v shall be 20km/h ± 1km/h.
For automatic transmission vehicles, the gear selector shall be placed as specified by the
manufacturer for normal driving.
For manual transmission vehicles, the gear selector shall be placed in the highest gear
which can achieve the target vehicle speed with constant engine speed.

3.4. Measurement Readings and Reported Values
At least four measurements for each test condition shall be made on both sides of the
vehicle.
The first four valid consecutive measurement results for each test condition, within 2.0dB(A)
per side, allowing for the deletion of non-valid results, shall be used for the calculation of the
intermediate or final result.
If a sound peak obviously out of character with the general sound pressure level is
observed, that measurement shall be discarded. For measurement of a vehicle in motion
(forward and reversing) outdoor, the maximum A-weighted sound pressure level indicated
during each passage of the vehicle between AA’ and PP’ (L ) shall be noted for each
microphone position, to the first significant digit after the decimal place (for example XX,X).
For measurement of a vehicle in motion indoor and in standstill (forward and reversing), the
maximum A-weighted sound pressure level indicated during each period of 5s for each
microphone position, L , shall be noted, to the first significant digit after the decimal place
(for example XX,X).
L shall be corrected according to Paragraph 2.3.2 to obtain L .
For each maximum A-weighted sound pressure level, the corresponding one-third-octave
spectrum shall be reported for each microphone position. No background correction shall be
applied to any measured one-third octave result.
3.5. Data Compilation and Reported Results
For each test condition described in Paragraph 3.3., the background corrected results,
L , and the corresponding one third octave spectra of both sides of the vehicle
individually shall be arithmetically averaged and rounded to the first decimal place.
The final A-weighted sound pressure level results L , L and L to be reported are
the lower values of the two averages of both sides, rounded to the nearest integer. The final
one third octave spectra to be reported are the spectra corresponding to the same side as
the reported A-weighted sound pressure level.

4.3. Test Methods
4.3.1. Method (A) – Outdoor Facility and Vehicle in Motion
The vehicle shall be operated in the same outdoor test facility and according to the same
general operating condition as for the vehicle constant speed testing (Paragraph 3.3.2).
The vehicle sound emission shall be measured at target speeds of 5km/h to 20km/h in steps
of 5km/h with a tolerance of ±2km/h for the speed of 10km/h or less and of ±1km/h for any
other speeds. The speed of 5km/h is the lowest target speed. If the vehicle cannot be
operated at this speed within the given precision, the lowest possible speed below 10km/h
shall be used instead.
4.3.2. Method (B) and Method (D) – Outdoor/Indoor Facility and Vehicle in Standstill
The vehicle shall be operated in a test facility where the vehicle can accept an external
vehicle speed signal to the AVAS simulating vehicle operation. The microphone locations
shall be as for the complete vehicle test conditions as specified in Figure 2a of the Appendix
to this Annex. The front plane of the vehicle shall be placed on Line PP’.
The vehicle sound emission shall be measured at simulated speeds of 5km/h to 20km/h in
steps of 5km/h with a tolerance of ±0.5km/h for each test speed.
4.3.3. Method (C) – Indoor Facility and Vehicle in Motion
4.3.4. Method (E)
The vehicle shall be installed in an indoor test facility where the vehicle can operate on a
chassis dynamometer in the same manner as outdoors. All microphone locations shall be as
for the vehicle test conditions as specified in Figure 2a of the Appendix to this Annex. The
front plane of the vehicle shall be placed on Line PP’.
The vehicle sound emission shall be measured at target speeds of 5km/h to 20km/h in steps
of 5km/h with a tolerance of ±2km/h for the speed of 10km/h or less and of ±1km/h for any
other speeds. The speed of 5km/h is the lowest target speed. If the vehicle cannot be
operated at this speed within the given precision, the lowest possible speed below 10km/h
shall be used instead.
The AVAS shall be mounted rigidly in an indoor facility, by means of the equipment
indicated by the manufacturer. The microphone of the measuring instrument shall be placed
at 1m distance from the AVAS in the direction where the subjective sound level is greatest
and placed at a height of approximately the same level as the sound radiation of the AVAS.
The sound emission shall be measured at simulated speeds of 5km/h to 20km/h in steps of
5km/h with a tolerance of ±0.5km/h for each test speed.

Target speed
Table 4
Analysis of the Shifted Frequency per Target Condition per Side
Test run per
target
condition
Reported speed
(average per
sample segment)
Determined
frequency of
interest
(f )
Reported Speed
per target
condition
(average of the
reported speeds)
Reported
frequency of
interest per
target condition
(f )
km/h No km/h Hz km/h Hz
1
5
2
3
4
1
10
2
3
4
1
15
2
3
4
1
20
2
3
4
For all other test methods the derived frequency spectrum shall directly be used for the
further calculation.

Table 5
Report Table, to be Completed for Each Frequency Analysed
Test Results at Target Speeds
5km/h
(Reference)
10km/h 15km/h 20km/h
Reported Speed
km/h
Frequency, f
, Left Side
Hz
Frequency, f
, Right Side
Hz
Frequency Shift, Left Side
%
n.a.
Frequency Shift, Right Side
%
n.a.

Figure 3
Minimum Space to be Qualified as Semi-Anechoic Chamber
Figure 4
Background Noise Parameter

Figure 6
Background Noise Requirements for Analysis in One-third-octave Bands

Figure 7b
Test Procedures for Measurement of Frequency Shift, Method A

Regulation on the Approval of Quiet Road Transport Vehicles (QRTV).