1.METHOD OF MEASUREMENTU.K.
The measurement is performed at microphone positions 2 and 6 as shown in Figure 1 of the Appendix, with the vehicle stationary. The highest A-weighted sound level shall be registered during venting the pressure regulator and during ventilating after the use of both the service and parking brakes.
The noise during venting the pressure regulator is measured with the engine at idling speed. The ventilating noise is registered while operating the service and parking brakes; before each measurement, the air-compressor unit has to be brought up to the highest permissible operating pressure, and then the engine switched off.