Auto & Marine Systems

Noise, Vibration & Harshness Diagnostic Tester

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 analog meter. External noises do not influence the reading.

 

There are extra features available on the NVH tester:

 

· A wind noise probe and diagnosing section.

· A hand held probe for static motor noise and plastic component noise diagnostics.

· An operation to decrease the sensitivity of the tester.

· An extended scale on the main meter for high readings.

· A “record” feature, which allows up to 2 hours of road test to be recorded.

 

This is detailed below;

The NVH unit has eight different memory blocks, each containing a total of 1000 memory locations. Each memory location can store the readings from all seven channels (six plus probe input) and the status indicators.  There are different sampling rates available, and on screen indication to indicate whether a memory block has data stored in it. A bar graph indicates the amount of remaining memory in the current memory block.  This can be downloaded via dedicated NVH software to a PC. The immediate benefits of this are;

 

· 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.

 

The LCD screen displays all settings, selections, noise levels and recording. The latest generation of the NVH Tester is fully digitalized. Updating and upgrading is software driven and available from the internet. The NVH Tester is equipped with PC interface.

 

Remember, finding a noise requires a methodical approach, which can take a lot of time. Vehicles have become better insulated against noise, and hence the noises heard inside are a mixture of a number of outside noises. As it is impossible to extend the sensitive human ear outside the vehicle to isolate mechanical noises, one needs the correct tool to do so.

By using the NVH Diagnostic Tester, this is easily achieved.

 

TECHNICAL SPECIFICATIONS

 

The complete NVH kit consists of the following:

 

· 1 x Hand held portable control unit with LCD display and serial interface, headphone Sockets, power input socket, and sensor input sockets.

· Six colour coded magnetic sensors.

· Two Hand probes, one open probe and one closed probe

· Two power cords

· One set of headphones

· Serial interface cable for PC

· NVH download software on CD Rom

· Carry case

· Sensor location pad.

· Packing case.

 

Weight: 7kg

Operating Voltage: 12V DC –24V DC