noise peak in power spectra by 6259

[USCyf]

Hi All,

I'm using a NI 6259 to aquire analog voltage signals with LabView SignalExpress. For test, I'm giving a 3Hz 1V sine signal to it. my sampling rate is 12.8kHz, 128k sample to read, and I'm using continuous samples, input range is 2 to -2 volt.

My problem is there are noises in aquired signals, as you can see from below picture, there are several peaks in the power spectra. Some of them looks like AC electrical noise from the power supply (120Hz, 240Hz).

My question is, how can get rid of these noises? (or shield) Thank you so much for your help.

Fang

[Emily-C]

Hi USCyf,

You can add a filter step to your SignalExpress project to remove or attenuate unwanted frequencies.

This page of the LabVIEW SignalExpress Help has more details on your options for creating a filter in SignalExpress.

This Developer Zone example has a SignalExpress project with a filter so you can see how to set it up.

I hope this helps!