BNC-2090A noise near zero frequency

[imperial-aero]

Hi,

I'm trying to read analog signals from a number of microphones using a BNC-2090A terminal and a PCI-6229 DAQ board.

My problem is, I have a signal close to zero frequency (probably the DC component of the terminal block). This isn't a problem when the amplitude of my microphone signals are larger than this 'noise' signal. However, sometimes, this noise signal has a larger amplitude.

Is there a way to remove this? Using, perhaps, some sort of filter in my VI. I found that the frequency is always very close to zero. Usually within the first 3 bins of my FFT frequency resolution.

Thank you.

[rsw]

Hi,

A few KB's you may find useful with regards to the noise you are seeing:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000001DdSnSAK&l=en-US

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9oBSAS&l=en-US

https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

All the best,

[imperial-aero]

Hi,

Thank you so much for your reply. The first KB article that you provided had the solution. As stated on the article, all I did was set the RSE/NRSE switch to RSE mode and also set my VI to RSE Input Configuration and it removed all the noise I was seing.

Cheers.