How can I filter thermocouple noise using a TC-2095 and SCXI-1102c?

[rlyles]

Hello all,

I currently have four TC-2095s connected to SCXI-1102c cards inside a SCXI-1001 chassis. These thermocouples are floating and I have been getting a fair amount of noise (3-phase 400 Hz and even 60 Hz noise) when we power on some equipment such as blowers and fans. Using this current set up, how can I filter the noise? Or do would I need to set up a new hardware configuration (i.e. SCXI-1102 cards)?

[Patrick_NI · Accepted solution]

Hi RALoo, 

The 1102C has a lowpass filter with a cutoff at 10kHz, so you will not be able to filter in hardware with your current setup.  

Your first option would be to use a software filter.  LabVIEW has several functions which accomplish this. More information on this can be found here: http://zone.ni.com/reference/en-XX/help/371361J-01/lvanls/filter_vis/

The second option would be to change to SCXI 1102 cards as you suggested.  The lowpass filter of the 1102 has a selectable cutoff frequency at 2 Hz, which will stop the 400 and 60Hz noise from affecting your readings.

[rlyles]

Thank you Patrick! I suspected that was the case.