scxi-1520 auto zero mode

[rberger]

I have an SCXI-1520 and a 1314 terminal block in which I want strain guage measurements. In MAX when I configure a DAQmx Channel, you get an option to auto zero once before an acquisition. Does this mean the DAQ driver will take the first measurement as zero strain and subsequently use this first reading to offset all measurements afterwards?

Thanks
Robert

[Sean_C.]

Hello Robert,

Thank you for contacting National Instuments.

You are partially correct. In AutoZero Mode, NI-DAQ shorts the input to ground and subtracts that measurement from all subsequent samples. It is basically a quick calibration technique.

What you described is more closely related to offset null compensation where potentiometers are adjusted until the wheatstone bridge reads 0 Volts at 0 strain.

Let me know if you have further questions.

Sincerely,

Sean C.
Applications Engineer
NAtional Instruments