USB-6002 pressure gauge readings give strange step function

[victorkangnz]

Hi all,

I have the current set-up below:

- OMEGA pressure gauge connected to signal amp connected to USB-6002, finally connected to laptop (powered by AC adaptor) via USB

- Differential mode

- I am using a MatLab program to capture the data

I am seeing this step-wise function in the Volts (V) vs Time plot (s). Any idea why this is happening? The set-up is well grounded. I have attached a sample 10 sec data at 100 Hz.

Thank you in advance for your help!

Victor

[victorkangnz]

Addendum: This quantised effect is not present in RSE mode (Volts vs time (s))

[Kevin_Price · Accepted solution]

At a glance, it sure looks like A/D quantization.  Note that both the X and Y axes in your second posting have a significantly different scale than in your first.  The quantization is probably still there, it's just obscured by all the additional noise and the much wider view.

-Kevin P

[victorkangnz]

Thank you very much, Kevin!