BS ISO 362-2:2009

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
5 Specification of the acceleration for vehicles of
  category L3 with PMR > 25
6 Instrumentation
7 Acoustical environment, meteorological conditions and
  background noise
8 Test procedures
9 Test report
Annex A (informative) - Technical background for development
        of vehicle noise test procedure based on in-use
        operation in urban conditions
Annex B (informative) - Measurement uncertainty - Framework for
        analysis according to ISO/IEC Guide 98-3
Annex C (informative) - Flowchart of the procedure for category
        L3 with PMR > 25
Annex D (informative) - Flowchart for vehicles of category L3
        with PMR <= 25
Annex E (informative) - Flowchart for vehicles of categories
        L4 and L5
Annex F (informative) - Indoor test operation
Bibliography

Describes an engineering method for measuring the noise emitted by road vehicles of categories L3, L4 and L5 under typical urban traffic conditions.

This part of ISO362 specifies an engineering method for measuring the noise emitted by road vehicles of categories L3, L4 and L5 under typical urban traffic conditions. It excludes vehicles of category L1 and L2, which are covered by ISO9645, vehicles of categories M and N covered by ISO362-1 and vehicles of categories L6 and L7.

The specifications are intended to reproduce the level of noise generated by the principal noise sources during normal driving in urban traffic, typically on roads with speed limits of 50km/h and 70km/h (see AnnexA).

The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle.

The test method requires an acoustical environment that is only obtained in an extensive open space. Such conditions are usually provided for

• type approval measurements of a vehicle,

• measurements at the manufacturing stage, and

• measurements at official testing stations.

NOTE1 The results obtained by this method give an objective measure of the noise emitted under the specified test conditions. It is necessary to consider the fact that the subjective appraisal of the noise annoyance of different classes of motor vehicles is not simply related to the indications of a sound measurement system. As annoyance is strongly related to personal human perception, physiological human conditions, culture and environmental conditions, there is a large variation and it is therefore not useful as a parameter to describe a specific vehicle condition.

NOTE2 Spot checks of vehicles chosen at random are rarely made in an ideal acoustical environment. If measurements are carried out on the road in an acoustical environment which does not fulfil the requirements stated in this International Standard, the results obtained can deviate appreciably from the results obtained using the specified conditions.