ZF 8HP - Auto


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Noise Vibration Harshness Testing


This technology we have acquired is to monitor graphically the vibration or harshness of sound on six different positions while driving of a vehicle. The sound gets recorded and can be printed in graphic format to show the before and after images of the recorded sound levels. This type of device pin points the problem area and can also be used to see what was gained during the repair on noise levels.


The N.V.H. Diagnostic Tester is a tool to pinpoint the source of noises.  

Operation of the tester has been approached from the workshops’ point of view, as they are the people who have to spend time trying to find all sorts of noises, squeaks and rattles.

Using up to six magnetic vibration sensors, the user positions them as required, and by doing a simple road test, can simulate the reported noise situation (i.e. around a left corner in second gear going uphill) and make a diagnosis. Taking a comparative reading between channels, viewing six level graphs on the LCD screen, as well as listening to each and every channel separately, allows the user to easily diagnose.

There are very specific advantages to the user by using vibration sensors as opposed to microphones.

These are:

The source of noise is generally a vibration

Vibration sensors are not influenced by outside ‘air’ noises, environmental noises (splashes etc) and tyre noise.

The magnetic vibration sensor picks up the vibration at the location where it is placed, and hence the closer it is placed to the point source, the greater the reading on the analogue meter. External noises do not influence the reading.


Noise profiles can be created of various situations

Service records of vehicle gearbox, wheel bearings, differentials and other items can be generated.

Comparisons of suspected faulty components can be checked against preset parameters on the PC, and definite decisions can be made on whether or not a part is worthy of a warranty claim or not.

This in turn means a customer does not have to be without their vehicle whilst warranty claims are being considered.

Warranty claim costs reduce, as it is more cost effective to email a file than transport a gearbox!

Data files are exportable to other spreadsheet applications and therefore databases can be created of acceptable noise profiles.