Regulation No. 28-00

Name:Regulation No. 28-00
Description:Audible Warning Devices.
Official Title:Uniform Provisions Concerning the Approval of: Audible Warning Devices and Motor Vehicles with Regard to their Audible Signals.
Country:ECE - United Nations
Date of Issue:1972-10-31
Amendment Level:00 Series, Supplement 5
Number of Pages:34
Vehicle Types:Bus, Car, Component, Heavy Truck, Light Truck, Motorcycle
Subject Categories:Miscellaneous
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Keywords:

audible, warning, system, approval, device, multiple, type, regulation, vehicle, sound, production, paragraph, number, test, vehicles, granted, level, pressure, mark, means, form, annex, manufacturer, authority, technical, devices, approved, rated, requirements, measured, communication, power, signals, current, frequency, microphone, extension, agreement, date, supplied, motor, voltage, pursuant, regard, measurement, categories, operation, tests, case, conformity

Text Extract:

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E/ECE/324
) Rev.1/Add.27/Amend.5
E/ECE/TRANS/505 )
February 7, 2018
STATUS OF UNITED NATIONS REGULATION
ECE 28-00
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF:
AUDIBLE WARNING DEVICES AND OF MOTOR
VEHICLES WITH REGARD TO THEIR AUDIBLE SIGNALS
Incorporating:
Supplement 1 to the 00 series of amendments
Date of Entry into Force: 07.02.84
Supplement 2 to the 00 series of amendments
Date of Entry into Force: 08.01.91
Corr. 1 to Supplement 2 to the 00 series of amendments
Dated: 16.06.92
Supplement 3 to the 00 series of amendments
Date of Entry into Force: 28.12.00
Supplement 4 to the 00 series of amendments
Date of Entry into Force: 20.01.16
Supplement 5 to the 00 series of amendments
Date of Entry into Force: 10.10.17

REGULATION NO. 28
UNIFORM PROVISIONS CONCERNING THE APPROVAL OF AUDIBLE WARNING DEVICES AND
OF MOTOR VEHICLES WITH REGARD TO THEIR AUDIBLE WARNING SIGNALS
REGULATION
1. Scope
CONTENTS
I.
Part I: Audible warning device, audible warning system, multiple audible warning system
2.
Definitions
3.
Application for approval
4.
Markings
5.
Approval
6.
Specifications
7.
Modification and extension of approval of the type of the audible warning device, audible warning
system, multiple audible warning system
8.
Conformity of production
9.
Penalties for non-conformity of production
10.
Production definitively discontinued
II.
Part II: Audible warning signals for motor vehicles
11.
Definitions
12.
Application for approval
13.
Approval
14.
Specifications
15.
Modification and extension of approval of vehicle type
16.
Conformity of production
17.
Penalties for non-conformity of production
18.
Production definitively discontinued
19.
Names and addresses of Technical Services responsible for conducting approval tests and Type
Approval Authorities
ANNEXES
1A
1B
Communication concerning the approval (or refusal or withdrawal of approval or production
definitely discontinued) of a type of audible warning device, audible warning system, multiple
audible warning system for motor vehicles, pursuant to UN Regulation No. 28
Communication concerning the approval (or refusal or withdrawal of approval or production
definitely discontinued) of a vehicle type with regard to its audible warning signals pursuant
to UN Regulation No. 28
2 Arrangement of the approval marks
3 Qualification criteria for anechoic environment
4 Microphone positions for measurements of acoustic parameters of audible warning device,
audible warning system, multiple audible warning system
5 Microphone positions for measurements of audible warning signals of motor vehicles

2.5. "Type of audible warning device (audible warning system, multiple audible warning
system)" means audible warning devices (audible warning systems, multiple audible
warning systems) not differing essentially from each other with respect to such matters as:
2.5.1. Trade name or mark;
2.5.2. Base designation:
2.5.2.1. For vehicles of Categories L to L of a power less than or equal to 7kW (Class I);
2.5.2.2. For vehicles of Categories M, N and L to L of a power greater than 7kW (Class II);
2.5.3. Principles of operation;
2.5.4. Audible warning devices, audible warning systems, multiple audible warning systems with
electrical supply:
2.5.4.1. Type of electrical supply (direct or alternating current);
2.5.4.2. Shape and dimensions of diaphragm(s);
2.5.4.3. Rated voltage;
2.5.5. Audible warning devices, audible warning systems, multiple audible warning systems
supplied directly from an external compressed air source:
2.5.5.1. Rated operating pressure;
2.5.6. Outer shape of a case;
2.5.7. Shape or kind of sound outlet(s);
2.5.8. Rated sound frequency or frequencies;
2.5.9. Shape and dimensions of rigid connections for audible warning system, multiple audible
warning system.
3. APPLICATION FOR APPROVAL
3.1. The application for approval of a type of audible warning device, audible warning system,
multiple audible warning system shall be submitted by its manufacturer or by his duly
accredited representative.
3.2. It shall be accompanied by a duly filled technical information document, either in paper
format in triplicate or alternatively upon agreement with the Type Approval Authority in
electronic format. A model of the technical information document is shown in Annex 1A.
3.3. In addition, the application for approval shall be accompanied by two samples of the type of
audible warning device, audible warning system, multiple audible warning system.
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.

5.6. Annex 2, Section I, to this Regulation gives an example of the arrangement of the approval
mark.
5.7. The Type Approval Authority or its duly accredited technical service shall verify the
arrangements of the marks for ensuring effective control of the conformity of production
before type approval is granted.
6. SPECIFICATIONS
6.1. General Specifications
6.1.1. The audible warning device, audible warning system, multiple audible warning system shall
emit a continuous and uniform sound; its acoustic spectrum shall not vary substantially
during its operation.
For audible warning devices, audible warning system, multiple audible warning system
supplied with alternating current, this requirement shall apply only at constant generator
speed, within the range specified in Paragraph 6.3.4.2.
The type approval tests shall be carried out on two samples of each type submitted by the
manufacturer for approval; both the samples shall be subjected to all the tests and must
conform to the technical specifications laid down.
6.1.2. The audible warning device, audible warning system, multiple audible warning system shall
have acoustic characteristics (spectral distribution of the acoustic energy, sound pressure
level) and mechanical characteristics such that it passes, in the order indicated, the tests
according to Paragraphs 6.3. and 6.4.
6.2. Measuring Instruments
6.2.1. Acoustic Measurements
6.2.1.1. When no general statement or conclusion can be made about conformance of the sound
level meter model to the full specifications of IEC 61672-1:2013 , the apparatus used for
measuring the sound pressure level shall be a sound level meter or equivalent
measurement system meeting the requirements of Class 1 instruments as described in
IEC 61672-3:2013 . Measurements shall be carried out using the "fast" response of the
acoustic measurement instrument and the "A" weighting curve as described in
IEC 61672-1:2013 . When using a system that includes a periodic monitoring of the
A-weighted sound pressure level, a reading should be made at a time interval not greater
than 30ms.
When measurements of the sound pressures in the one-third mid-band frequencies 2,000,
2,500 and 3,150Hz are carried out for one-third octaves, the instrumentation shall meet all
requirements of IEC 61260-1-2014, Class 1. The sound pressure level in the mid-band
frequency 2,500Hz shall be determined by adding the quadratic means of the sound
pressures in the one-third mid-band frequencies 2,000, 2,500 and 3,150Hz.
When measuring the rated sound frequency (or frequencies), the digital sound recording
system shall have at least a 16 bit quantization. The average auto power spectrum shall be
determined, using a Hanning window and at least 66.6% overlap averages.
The instruments shall be maintained and calibrated in accordance with the instructions of
the instrument manufacturer.

6.3. Measurement of the Sound Characteristics
6.3.1. The audible warning device, audible warning system, multiple audible warning system
should, preferably, be tested in an anechoic chamber. Alternatively, it may be tested in a
semi-anechoic chamber or in an open space . In these cases, precautions shall be taken to
avoid reflections from the ground within the measuring area (for instance by erecting a set of
absorbing screens). The wind speed shall be not more than 5m/s. The ambient noise level
shall be at least 10dB lower than the sound pressure level to be measured.
If the test facility shall be qualified as an anechoic environment it shall meet requirements of
Annex 3.
6.3.2. The audible warning device, audible warning system, multiple audible warning system to be
tested and the microphone shall be placed at the same height. This height shall be
1.20 ± 0.05m.
In alternative, the audible warning device, audible warning system, multiple audible warning
system to be tested and the microphone may be placed in another traverse line which
complies with Annex 3 specification for anechoic environment.
The microphone shall be so placed that its diaphragm is at a distance of 2.00 ± 0.05m from
the plane of the sound outlet of the audible warning device, audible warning system,
multiple audible warning system. The microphone must be positioned facing the front
surface emitting sound of the audible warning device, audible warning system, multiple
audible warning system in the direction in which the maximum sound level can be
measured. (See Figures in Annex 4).
In the case of audible warning device with several outlets, the distance shall be determined
in relation to the plane of the nearest outlet to the microphone.
6.3.3. The audible warning device, audible warning system, multiple audible warning system shall
be mounted rigidly, by means of the equipment indicated by the manufacturer, on a support
whose mass is at least ten times that of the audible warning device, audible warning
system, multiple audible warning system under test and not less than 30kg. In addition,
arrangements must be made ensuring that reflections on the sides of the support and its
own vibrations have no appreciable effect on the measuring results.
6.3.4. The audible warning device, audible warning system, multiple audible warning system shall
be supplied with current, as appropriate, at the following voltages:
6.3.4.1. In the case of audible warning device, audible warning system, multiple audible warning
system supplied with direct current, at a voltage measured at the terminal of the electric
power source of 13/12 of the rated voltage;

6.3.8. The specifications indicated above shall also be met by an audible warning device, audible
warning system, multiple audible warning system subjected to the endurance test referred to
in Paragraph 6.4. below, with the supply voltage varying between 115% and 95% of its rated
voltage for audible warning device, audible warning system, multiple audible warning
system supplied with direct current or, for audible warning device, audible warning system,
multiple audible warning system supplied with alternating current, between 50% and 100%
of the maximum speed of the generator indicated by the manufacturer for continuous
operation.
6.3.9. The time lapse between the moment when the audible warning device audible warning
system, multiple audible warning system is actuated and the moment when the sound
reaches the minimum value prescribed in Paragraph 6.3.7.1. above shall not exceed 0.2s
measured at an ambient temperature of 20 + 5°C. This provision is applicable, inter alia, to
pneumatic or electro-pneumatic audible warning device, audible warning system, multiple
audible warning system.
6.3.10. Pneumatic or electro-pneumatic audible warning device, audible warning system, multiple
audible warning system shall, when operating under the power supply conditions
established by the manufacturers, satisfy the same acoustic requirements as are prescribed
for electrically operated audible warning device, audible warning system, multiple audible
warning system .
6.3.11. To confirm the rated sound frequency (or frequencies) of audible warning device, audible
warning system, multiple audible warning system the tests to measure this parameter using
a spectrum analyser with a frequency resolution of at least 1Hz shall be conducted. The
measured frequency (or frequencies) of the audible warning device, audible warning
system, multiple audible warning system may differ from the rated sound frequency (or
frequencies) no more than 10%.
6.4. Endurance Test
6.4.1. The audible warning device, audible warning system, multiple audible warning system shall
be supplied with current at the rated voltage and with the connecting lead resistances
specified in Paragraphs 6.3.4. to 6.3.6. above, and operated, respectively:
10,000 times for audible warning device, audible warning system, multiple audible warning
system intended principally for vehicles of Categories L to L with a power less than or
equal to 7kW
50,000 times for audible warning device, audible warning system, multiple audible warning
system intended principally for vehicles of Categories M, N and L to L with a power greater
than 7kW, each time for one second followed by an interval of 4s.
During the test, the audible warning device, audible warning system, multiple audible
warning system shall be ventilated by an air current having a speed of approximately 10m/s
and the electro-pneumatic audible warning device, audible warning system, multiple audible
warning system may be lubricated with the oil recommended by the manufacturer after
every 10,000 times of operation.
6.4.2. If the test is made in an anechoic chamber, the chamber shall be large enough to ensure
normal dispersal of the heat released by the audible warning device, audible warning
system, multiple audible warning system during the test.

9. PENALTIES FOR NON-CONFORMITY OF PRODUCTION
9.1. The approval granted to a type of audible warning device, audible warning system, multiple
audible warning system pursuant to this Regulation may be withdrawn if the conditions set
forth in Paragraph 8.1. are not complied with or if the audible warning device, audible
warning system, multiple audible warning system fails to pass the checks referred to in
Paragraph 8.2. above.
9.2. Should a Party to the Agreement applying this Regulation withdraw an approval which it has
previously granted, it shall forthwith notify the other Contracting Parties applying this
Regulation by means of a copy of the approval form bearing at the end in large letters the
statement, signed and dated: "APPROVAL WITHDRAWN".
10. PRODUCTION DEFINITIVELY DISCONTINUED
If the holder of an approval granted pursuant to this Regulation discontinues the production
of the type of audible warning device, audible warning system, multiple audible warning
system approved, he shall inform the authority which granted the approval. Upon receipt of
the communication this authority shall inform the other Parties to the Agreement applying
this Regulation by means of a copy of the approval form bearing at the end in large letters
the statement, signed and dated: "PRODUCTION DISCONTINUED".
II.
Part II. Audible Warning Signals of Motor Vehicles
11. DEFINITIONS
For the purpose of this Regulation,
11.1. "Approval of the motor vehicle" shall be understood to mean approval of a vehicle type
with regard to its audible warning signal;
11.2. "Vehicle type" shall be understood to mean vehicles not essentially different from another
with respect to such matters as:
11.2.1. The number and type(s) of audible warning devices and/or audible warning systems and/or
multiple audible warning systems fitted on the vehicle;
11.2.2. The mountings used to fit the audible warning device(s) and/or audible warning system(s)
and/or multiple audible warning system(s) to the vehicle;
11.2.3. The position of the audible warning device(s) and/or audible warning system(s) and/or
multiple audible warning system(s) on the vehicle;
11.2.4. The rigidity of the parts of the structure on which the audible warning device(s) and/or
audible warning system(s) and/or multiple audible warning system(s) is (are) mounted;
11.2.5. The shape and materials of the bodywork at the front of the vehicle which might affect the
level of the sound emitted by the audible warning device(s) and/or audible warning
system(s) and/or multiple audible warning system(s) and have a masking effect.

13.8. Annex 2, Section II, to this Regulation gives an example of the arrangement of the approval
mark.
13.9. 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.
14. SPECIFICATIONS
14.1. General Specifications
14.1.1. The audible warning device, audible warning system, multiple audible warning system shall
be so designed, constructed and assembled as to enable the vehicle, in normal use, despite
the vibration to which it may be subjected, to comply with the provisions of this Regulation.
14.1.2. The audible warning device(s), audible warning system(s), multiple audible warning
system(s) and its (their) mounting elements to the vehicle shall be so designed, constructed
and assembled as to be able to reasonably resist the corrosive phenomena to which it is
exposed with regards to the conditions of use of the vehicle, including regional climate
differences.
14.2. Specifications Regarding Sound Levels
14.2.1. The sound made by the audible warning device(s), audible warning system(s), multiple
audible warning system(s) fitted to the vehicle type submitted for approval shall be
measured by the methods described in Paragraph 14.3.;
14.2.2. Measured under the conditions specified in Paragraphs 14.3. the sound-pressure level of
the audible warning signal tested shall be at least:
(a)
Equal to 83dB (A) and not more than 112dB (A) for the signals of vehicles of
Categories L to L of a power less than or equal to 7kW;
(b) Equal to 87dB (A) and at most 112dB (A) for the signals of vehicles of Categories M,
N and L to L of a power greater than 7kW.
14.2.3. The values measured in accordance with the provisions of Paragraph 14.3 shall be entered
in the test report and a communication corresponding to the model shown in Annex 1B.
14.3. Methods of Measurement on Stationary Vehicle
14.3.1. The vehicle shall comply with the following specifications:
14.3.1.1. The audible warning device(s), audible warning system(s), multiple audible warning
system(s) fitted on the vehicle shall be of a type approved under this Regulation (Part I);
Audible warning devices of Class II approved under this Regulation in its original form, and
therefore not bearing the Symbol II in their approval mark, may continue to be fitted to
vehicle types submitted for approval pursuant to this Regulation.

16. CONFORMITY OF PRODUCTION
The conformity of production procedures shall comply with those set out in the
1958 Agreement, Schedule 1 (E/ECE/TRANS/505/Rev.3) with the following requirements:
16.1. A vehicle approved under this Regulation shall be so manufactured as to conform to the
type approved by meeting the requirements set forth in Paragraph 14 above.
16.2. The Type Approval 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 once every two years.
17. PENALTIES FOR NON-CONFORMITY OF PRODUCTION
17.1. The approval granted to a vehicle type pursuant to this Regulation may be withdrawn if the
conditions set forth in Paragraph 16.1. above are not complied with, or if the vehicle fails to
pass the checks referred to in Paragraph 16.2. above.
17.2. Should a Party to the Agreement applying this Regulation withdraw an approval which it has
previously granted, it shall forthwith notify the other Contracting Parties applying this
Regulation by means of a copy of the approval form bearing at the end in large letters the
statement, signed and dated: "APPROVAL WITHDRAWN"
18. PRODUCTION DEFINITIVELY DISCONTINUED
18.1. 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 1B to this Regulation.
19. NAMES AND ADDRESSES OF TECHNICAL SERVICES RESPONSIBLE FOR
CONDUCTING APPROVAL TESTS AND OF TYPE APPROVAL AUTHORITIES
The Contracting Parties to the 1958 Agreement applying this Regulation shall communicate
to the United Nations Secretariat the names and addresses of the Technical Services
responsible for conducting approval tests and of the Type Approval Authorities which grant
approval and to which forms certifying approval or extension or refusal or withdrawal of
approval, issued in other countries, are to be sent.

0.4.
Class:
................................................................................................................................................
0.5.
Company name and address of manufacturer: ...................................................................................
0.6.
Name and address of the manufacturer's representative (if any): ......................................................
0.7.
Names and address(es) of assembly plant(s): ...................................................................................
Section II
1.
Additional information (where applicable): See Addendum
2.
Technical service responsible for carrying out the tests: ....................................................................
3.
Date of test report: ...............................................................................................................................
4.
Number of test report: .........................................................................................................................
5.
Remarks (if any): See Addendum
6.
Place: ...................................................................................................................................................
7.
Date: ....................................................................................................................................................
8.
Signature: ............................................................................................................................................
9.
Reasons for Extensions: .....................................................................................................................
Attachments:
Information package
Test report(s)

0. General
ANNEX 1A – APPENDIX 1
TECHNICAL INFORMATION DOCUMENT FOR TYPE APPROVAL OF
AUDIBLE WARNING DEVICE
AUDIBLE WARNING SYSTEM
MULTIPLE AUDIBLE WARNING SYSTEM FOR MOTOR VEHICLES
0.1. Make (trade name (mark) of manufacturer): .............................................................................
0.2. Type or commercial description: ...............................................................................................
0.3. Means of identification of type if marked: .................................................................................
0.3.1. Location of that marking: ...........................................................................................................
0.4. Class: ........................................................................................................................................
0.5. Company name and address of manufacturer: ........................................................................
0.6. Name and address of the manufacturer's representative (if any): ............................................
0.7. Names and address(es) of assembly plant(s): .........................................................................
1. General construction characteristics;
1.1. Brief description of a principle of operation: pneumatic, electro-pneumatic, electro-magnetic
with resonator disc, electromagnetic with horn, etc.; .............................................................
1.2. Rated voltage(s), V; ................................................................................................................
1.2.1. Type of electrical supply (direct or alternating current); ............................................................
1.3. Rated operating pressure(s), MPa (kg/cm ); .........................................................................
1.4. Rated sound frequency (or frequencies), Hz; .........................................................................
1.5. Outer shape of case; .................................................................................................................
1.6. Shape and dimensions of diaphragm(s); ..................................................................................
1.7. Shape or kind of sound outlet(s); ..............................................................................................
1.8. Geometrical characteristics (internal length and diameter) of connecting line between
compressor or control and the audible warning device, audible warning system, multiple
audible warning system; ...........................................................................................................
1.9. Photographs and/or drawings; ..................................................................................................

ANNEX 1B
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 audible signals pursuant to UN Regulation No. 28
Approval No.: .002439
Extension No.: 00
Section I
0.1.
Make (trade name of manufacturer of vehicle): ........................................................................
0.2.
Type: .........................................................................................................................................
0.3.
Means of identification of type if marked on the vehicle:
........................................................
0.3.1.
Location of that marking: ...........................................................................................................

ADDENDUM TO THE COMMUNICATION FORM NO. 002439 , EXTENSION NO.: 00
1. Additional Information
1.1. Make (trade name (mark) of manufacturer) of audible warning device(s), audible warning
system(s), multiple audible warning system(s): ........................................................................
1.2. Type or commercial description of audible warning device(s), audible warning system(s),
multiple audible warning system(s): ..........................................................................................
1.3. Means of identification of type if marked on the audible warning device(s), audible warning
system(s), multiple audible warning system(s): ......................................................................
1.4. The approval number and issuing authority of audible warning device(s), audible warning
system(s), multiple audible warning system(s): ........................................................................
2. Test results
2.1. Power supply used: Vehicle battery only/battery with vehicle engine at idle/external power
supply : ....................................................................................................................................
2.2. A-weighted sound pressure level: ........................................................................................ dB
3. Remarks

1. General construction characteristics of the mountings of the audible warning device(s),
audible warning system(s), multiple audible warning system(s) on the vehicle
1.1. Photographs or drawings of a representative vehicle: ..............................................................
1.2. Drawings of the mountings and mounting position(s) of the audible warning device(s):
1.3. Description of the component materials in front of the audible warning device(s), audible
warning system(s), multiple audible warning system(s): ..........................................................
1.4. A list of the components used in production on which the audible warning device(s), audible
warning system(s), multiple audible warning system(s) are fitted, duly identified, with
indication of the materials used;
1.5. Detailed drawings of all the components on which the device(s) are fitted, used in
production;
Signed: ......................................................................................................................................
Position in company: .................................................................................................................
Date: ..........................................................................................................................................

Model B
The
above approval mark affixed to a vehicle shows that the vehicle typee concerned has been
approved in the
Netherlands (E 4), pursuant to UN
Regulationss Nos. 28 and 33. The
approval
numbers indicate that, at the dates when the respective approvals were granted, UN Regulation
No. 28 and UN Regulation No. 33 were in their original form.

(All dimensions are in m)
Figure 1

B. In Case of Audible Warning System
The
reference point is the centre of a figure connecting the sound emitting opening centre of each
audible warning
device.
All dimensions are in m

Audible Warning Devices.