Ruído, vibração e aspereza

501-25-92 Body Repairs - General Information 501-25-92 DESCRIPTION AND OPERATION TO BE UPDATED LATER Item Description 1 NVH element 2 PU adhesive For the exact installation position of an NVH element, please refer to the vehicle-specific repair instructions. If an NVH element is to be reused, the bonding on the body panel must be detached. To do this, the body panel must be heated in the area around the NVH element. The bonding can be detached at approx. 170° C. The damaged panel part can now be carefully dismantled. Before installing the new panel part, a PU adhesive must be applied to the contact areas between the panel and the NVH element. Test techniques, measuring devices The shortest route to an accurate diagnosis results from: ‡ general information on the problem vehicle and a comparison test with a vehicle of the same construction, without NVH problems. ‡ vehicle history, including repair history and usage patterns. ‡ condition history, especially any relationship to repairs or sudden change. ‡ knowledge of probable causes. ‡ application of diagnosis procedures in which the vehicle is split into corresponding areas. The diagnosis and correction of noise, vibration and harshness concerns requires: ‡ general information on the problem vehicle and a comparison test with a vehicle of the same construction, without NVH problems. ‡ vehicle history, including repair history and usage patterns. ‡ condition history, especially any relationship to repairs or sudden change. ‡ knowledge of probable causes. ‡ application of diagnosis procedures in which the vehicle is split into corresponding areas. NOTE: The diagnosis of droning problems is one of the most difficult tasks in the NVH area. With the exception of installed components under stress, a certain diagnosis of droning problems (or boom) on customer vehicles makes great demands on the automotive technician. The performance of measuring equipment and their practice-orientated application can only be obtained through suitable instruction (NVH training). The successful use of these devices requires a great deal of experience on the part of the user. The diagnosis and correction of noise, vibration and harshness concerns requires: ‡ a road or system test to determine the exact nature of the concern. Analysis of possible causes: ‡ checking of the cause and elimination of the faults found. ‡ a road test or system test to make sure the concern has been corrected or brought back to within an acceptable range. ‡ It is often very difficult to locate noises that are audible in the passenger compartment based on the problem description provided by the customer and the road tests performed. The direction of the noise can be detected subjectively, but the source of the noise cannot be found. NOTE: For a selection of simple test tools, see the wind noises section. Electronic NVH tester