scope:

This International Standard specifies a survey method for measuring the noise produced by a stationary road vehicle at a readily obtainable site having specific characteristics. The method is intended to check vehicles in use, and also to determine variations in the noise emitted by different parts of the vehicle under test, which can result from the wear, maladjustement or modification of particular components, when the defect does not appear by visual inspection; the partial or complete removal of devices reducing the emission of certain noises. These variations shall be determined by comparing the measurements with reference measurements made under similar conditions, for example during the type approval of the vehicle.