Acquiring AI in PCI 6143

[hussey]

Hi

I am trying to acquire constant Analog signal of 65mV from a sensor to computer through PCI-6143 and for that used a DAQmx.

However the signal is constant but during acquisition it seems its oscillate, Here picture attached. How i can acquire constant signal without averaging.

I have tried, sample on demand,continuous sample and N samples mode but in every condition signal is varying.

Need suggestion to resolve error, without averaging my signal.

thanks in advanced

[NeilR · Accepted solution]

It looks like you may be picking up some 50Hz mains ..?

An article here about making analog measurements may help.

http://www.ni.com/tutorial/7113/en/#toc2

[hussey]

In multimeter its shows me constant values.

[NeilR]

What type of sensor are you using ?

[hussey · Accepted solution]

Thanks budy....

it was 50 Hz noise. It was coming from external power supply of my sensors and due to that original signal was continuously fluctuating.