ISO 6969:1981

International Standard @ 6969
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*ME)YHAPO~HAR OPTAHMJAUMR no CTAH&AF'TM3AUHM.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Road vehicles - Sound signalling devices - Tests after
*
mounting on vehicle
Véhicules routiers - Avertisseurs sonores - Essais après montage sur le véhicule
First edition - 1981-10-15
üi UDC 692.11.018.2 Ref. No. IS0 6969-1981 (E)
Descriptors : road vehicles, signal devices, sound signalling devices, tests, testing conditions, measurement.
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2 pages
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Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards institutes (IS0 member bodies). The work of developing Inter-
national Standards is carried out through IS0 technical committees. Every member
body interested in a subject for which a technical committee has been set up has the
right to be represented on that committee. International organizations, governmental
e
and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council.
International Standard IS0 6969 was developed by Technical Committee ISO/TC 22,
Road vehicles, and was circulated to the member bodies in December 1979.
It has been approved by the member bodies of the following countries :
India Romania
Austria
Belgium Italy South Africa, Rep. of
Brazil Korea, Dem. P. Rep. of Spain
Korea, Rep. of Sweden
Bulgaria
Egypt, Arab Rep. of Mexico United Kingdom
France New Zealand USSR
Germany, F.R. Poland
The member bodies of the following countries expressed disapproval of the document
on technical grounds :
Netherlands
USA
O International Organization for Standardization, 1981 O
Printed in Switzerland
INTERNATIONAL STANDARD IS0 6969-1981 (E)
Road vehicles - Sound signalling devices - Tests after
mounting on vehicle
1 Scope and field of application 4 Expression of results
This International Standard specifies the testing of sound The results of the measurements of the sound pressure levels
signalling devices conforming to IS0 512 to be carried out after shall be in relation to 2 x 10-5 Pa (N/m2), weighted in accor-
mounting on the vehicle. dance with curve A, and the results expressed in decibels (A).
The following specifications apply exclusively to the testing of
acoustical properties of sound signalling devices mounted on
new types of road vehicle.
5 Test conditions
5.1 Test site of vehicle and ambient conditions
2 References
The vehicle being placed on an open site as, for example, an
IS0 512, Road vehicles - Sound signalling devices -
open space of 50 m radius, the central part of which, being in-
Technical specifications. 1 1
tended for the execution of the measurements, shall be prac-
IS0 3833, Road vehicles - Types - Terms and definitions.
tically horizontal over at least 20 m radius, covered with con-
crete, asphalt or any similar material, and be free from long
IEC Publication 51, Recommendations for direct acting in-
grass, loose soil or ashes.
dicating electrical measuring instruments and their accessories.
Measurements shall be taken in clear weather. No other person
IEC Publication 179, Precision sound level meters.
than the observer taking the readings on the meter shall stay in
IEC Publication 225, Octave, half-octave and third-octave band
the vicinity of the sound signalling device or of the microphone,
filters intended for the analysis of sounds and vibrations.
since the presence of bystanders may have an appreciable in-
fluence on the meter readings.
3 Measuring apparatus
The ambient noise level within the entire range covered by fre-
quencies of components of the sound emitted by the sound
The measurement of sound pressure levels shall be made using
signalling device shall be at least 10 dB lower than the sound
a sound level meter conforming to IEC Publication 179. level of each of the components. However, this requirement is
not applicable to components with a measure
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