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USB-6002 pressure gauge readings give strange step function

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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

test.JPG

 

 

 

 

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

 

test2.JPG

 

 

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Solution
Accepted by topic author victorkangnz

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

CAUTION! New LabVIEW adopters -- it's too late for me, but you *can* save yourself. The new subscription policy for LabVIEW puts NI's hand in your wallet for the rest of your working life. Are you sure you're *that* dedicated to LabVIEW? (Summary of my reasons in this post, part of a voluminous thread of mostly complaints starting here).
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Thank you very much, Kevin!

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