noise & vibration

[BLAK]

Hi

We are collecting the data of a machine which produces noise & vibration. During each trial run we are getting different values can any one help to solve this problem.

Thanks

[RavensFan]

What kind of help do you expect?  You haven't provided any information.  What kind of problem do you have?  Post some data or screen shots that show what you are getting and explain how it is different from what you are expecting.

How To Ask Questions The Smart Way

[harryhs2000]

We are testing the Quality of the gears based on the noise and vibration produced when the bevel and the pinion gears mesh each other.

We Using SV DAQ NI PCI-447 and connected accelerometer and microphone for 1st and 4th channel respectively.

We are following signal harmonics method for the testing purpose. First, we acquire the data signals of both noise and vibration and process them by the same above method and judge wheatear the gear has some defects or not. (Based on the threshold values)

The problem is, each time when we run the machine, the noise and vibration signals which we acquire will be different due to this final results (Harmonic values) are also changing. We need some filters or any other solution so that we acquire noise and vibration only for gear mesh.

I uploaded a picture showing how we doing the test process for sound.

[RavensFan]

Have you considered the possibility that the noise and vibration signals might actually be varying from test to test due to other variables beyond your control?

Have ever successfully measured noise and vibration this way or know of anyone who has?

[harryhs2000]

This is the front panel desing for that testing process.

When we run the gears in two directions( clockwise and anticlockwise) ,we acquire the noise and vibration geneated and judge the gear quality.

[johnsold]

I suggest that you acquire an additional signal which measures the speed directly, such as an optical or magnetic pick up on the gear teeth.  Then you will have a signal proportional to the speed and you can synchronize the remainder of the analysis to that.

You might be able to get the speed from an FFT of the gear signal without another input if the data is clean enough.

Lynn