voltage amplitudes changes depending on sampling frequency (NI-9234)

[Enhorse]

Hi,

I have a qeustion about NI-9234 (vibration module). I connected one accelerometer (PCB 393B31) to this module and made a just simple code with Labview 2019.

The problem is the voltage amplitude is changing depending on how I set the sampling frequency (Signal lengths are the same).

The below screenshot shows the signal when I set a high sampling frequency (25.6 kHz).

The below screenshot shows the signal when I set a low sampling frequency (17 kHz).

As you can see, the amplitudes are different in the time-domain signals.

The accelerometer is attached to a bridge.

In the Labview, I set AC coupling, Pseudodiffferential mode.

I am not sure why the amplitude is changing by the sampling frequency.

[testproggie]

If your screen shots are real, the lower frequency sampling rate is 1706.67, not even close to 17kHz. I think I would need to see the vi to go further than that.