Can not stabilize or zero the output on the test panel

[Dr Dickie]

Hi, I am using a NI USB 6009 DAQ with a Kistler 50g accelerometer and a Kistler 5114 Power supply coupler (+/- 5 v)

On the NI test panel I can not get the signal to zero, it flickers around the -0.5 v. The signal responds to movement of the accelerometer OK.

I have tried new cabling to make sure there is no pinch on the cables and the problem is still there.

I am not sure what the input configuration on the test panel should be ie differential or RSE. Any suggestions? When RSE selected I get a signal hovering around +0.8, Differential -0.5V.

Any ideas what the problem is would be greatfully recieved.

Thanks

[Wayne.C]

I think you probably have this working.  Most sensors of this type will have an offset and you can expect some noise in the output signal.  The question is are the numbers you are observing correct for your sensor.  Can you give some more details about your sensor/supply setup.  What is expected fullscale output of your sensor at 50g?  Did your sensor come with any calibration info?

I would start with a differential input configuration on the DAQmx device.

[SheelaS]

Dr. Dickie,

I believe you spoke to Richard on the phone a day or two ago about this issue, and that he offered you a solution to try out.

I understand he had you wire up your accelerometer in differential mode, giving you the pins to connect to, and that this significantly reduced the offset.

He then suggested you wire in some bias resistors to minimise the noise offset you were seeing, with reference to this article https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

I was just wondering how you are gettign on, and what results you are now seeing?