Measurement of microvolts using Labview 7.0

[wwert]

I am using block ScXI 1303 to measure the signal in microvolts. But the noise is too high, so I applied amplifier before the signals go into the block. I can get amplifiered signal in millivolts at last.

But when I check the signals with a muitimeter before them go into the block, I get different values form those readings obtained by Labview.

So, how can I make them to be consistant with each other? Can I add or substract some value in the data collecting program to do that? How can I check it really work?

thanks


Wu

[Salvador_Santolucito]

Hi Wu,

Can we get some more information about your setup? How are you connecting your signal? What is the grounding scheme (of your signal and DAQ hardware)? What SCXI board are you using (the 1303 is the terminal block)? What VI are you using to obtion the signal in LabVIEW?

You said that you applied an amplifier before your signals go into the block, what type of amplifier is it? Does the SCXI board you have do amplification?

When you say that the signal is different, how is it different? Is it offset by a constant voltage? Are you seeing random noise but the signal shape is the same? Is it just plain wrong?

Thanks,
Sal