Double integrated accelerometer signals get noise after a long time

[db-vibration-balancing]

I used cDAQ 9178 and 5 NI 9230 with 10 accelerometer for vibration measurement. Display displacement signals (by double integrated accelerometer signals and filtered). Measurement is continuous. In the beginning the signals are cleared but after half hour one or two signal get noise (time waveform is not cleared). After stop application and run up again all signal are cleared again.

can someone help me to resolve this problem? I think filter module get over flow after a long time?

[Bob_Schor]

You may need to take a course on Digital Signal Analysis.  This is a bit outside my area of expertise.  Double integration of an accelerometer signal will give you "displacement", but any tiny error (in the form of both offset of the signal from 0 and gain from 1) will get magnified by the integration process -- designing a digital filter to "fix" the problem could be a challenge.  Got any EE friends/colleagues?

Bob Schor

[db-vibration-balancing]

Hi, the filter of labview is ok in half hour and just get noise for 1 or 2 channels after that time. If the filter is wrong it will affect all the time?