Standing noise

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Standing noise

Standing noise
Standing noise

The legislature does not stipulate any limit values ​​for the stationary noise of motorcycles. However, it is always determined and entered in the vehicle documents.

02/25/2003

The legislature does not stipulate any limit values ​​for the stationary noise of motorcycles. However, it is always determined and entered in the vehicle documents. This gives the police the opportunity to use relatively simple means to check the original condition of a vehicle during traffic checks. Because replacement silencers must not exceed the sound pressure level of the original system.

The examiner determines it through a near-field measurement. The measurement microphone is positioned 50 centimeters away from the outlet opening of the silencer. It points with its axis at a 45-degree angle to the end of the exhaust and is at least 20 centimeters away from the ground. It is aligned parallel to the ground.

If the motorcycle has several exhaust outlets that are not more than 30 centimeters apart, the tester measures the stationary noise on a central exhaust pipe. Or he places the measuring microphone at the end of the exhaust which is furthest away from the road surface.

If, on the other hand, the center-to-center distance of the damper ends is more than 30 centimeters, separate measurements are required at each individual mouth. The largest measured value is then decisive for the stationary noise.

The ground of the measuring area consists either of asphalt or of concrete. There must also be no sound-reflecting objects three meters around the vehicle. Interfering noises must be at least ten decibels below the sound pressure level to be measured. To determine the stationary noise, the testers let the engine rev up to half of the rated power speed, provided that this is over 5000 rpm. If it is less than or equal to this value, the engine must mobilize three quarters of the nominal speed. The measuring apparatus is switched on during the entire process: After reaching and briefly holding the test speed, the throttle grip is closed.

The maximum deflection of the pointer on the measuring device is decisive. The dB (A) values ​​read are rounded up or down to full decibels. In any case, three measurements are due. Only successive results that do not differ by more than two dB (A) from one another are eligible. The measurement result is the largest of the three values.

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