Vehicles Inspection Noise Quick Check Test Procedure PDF Requirement Manual


What is the purpose of the Noise Quick Check? The purpose of this test procedure is to enable vehicle inspectors to carry out an exhaust noise check with an acceptable noise meter to ensure that vehicle exhaust systems that have been modified to be noisier than OE remain well below the maximum noise levels specified in law (ie be below the noise limits specified in the VIRM).

Any vehicle that fails the Noise Quick Check needs to be made quieter and reinspected and/or referred to an LVV certifier for an Objective Noise Test (ONT). This quick check test procedure is therefore a simplified version of the ONT to ensure results are comparable to the ONT.

What type of vehicle can be tested? The quick check may be applied only to a vehicle of class LC, LD, LE, MA, MB, MC, MD1, MD2 or NA that is louder than when it was manufactured with its original exhaust system.

Test site specification The test environment must be such that exhaust noise readings can be achieved as accurately as possible with as little interference from other noise sources as possible. To achieve this, the test site must, within at least a 3 m radius from the noise meter microphone:

1. be an open outdoor site (if this is not practicable, a canopied site may be used provided the canopy is at least 3 m above the microphone).
2. be predominantly flat
3. be free from large sound-reflecting surfaces, including buildings, walls, billboards, vehicles, canopy/roof supports, trees or shrubs
4. have a solid surface, such as concrete or asphalt, that is free of any loose or sound-absorbing material.
It is important that a noisy background, eg due to road traffic or wind, is avoided. If in doubt, use the noise meter to measure the background noise either before or after the Noise Quick Check. The background noise must be at least 10 dBA lower than the relevant exhaust noise limit specified in the VIRM. Sharp noise interference such as car doors slamming or loud footsteps must also be avoided to prevent false readings.

Download Vehicles Inspection Noise Quick Check Test Procedure PDF Requirement Manual

 


Tagged Under : , , , , , , , Filed Under (Engine Manual) by m4d35 on 29-08-2010
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