Reducing Noise in Waveform - Tips & Techniques

[rama1001]

Hello,
I have a waveform that have noise when my pump stroke hit some mechanical part. i have converted the waveform into frequency domain to see the noise frequencies. I don't know the actual original frequency of the pump but i just decresed noise by stroke not touching the mechanical part(physically) and chekced for the original frequencies which are in around 170hz to 190Hz. When there is mechanical noise, frequencies are in 0 to 1kHz for small pump and 0 to 2kHz for big one. I desinged a program in LABview based amplitude leves and that is not at all efficient and more i need to change amplitude levels always for different kind of pumps.

Can some one help me how can i differentiate these mechanical noise from the time domain waveform or freq domain waveform. I just need some theoretical guidence and i can use again labview to make it practical. See the attchments for pictures at https://www.physicsforums.com/showthread.php?t=527895

and down here in FFT.

 

[Tom.G]

A simple bandpass filter at the desired signal frequency is the straight-forward approach.

Depending on the noise level, this can be a single RC high-pass stage followed by a single RC low-pass. I've even used an RC high-pass followed by a low bandwidth op-amp for needed gain. The op-amp then also serves as the low-pass stage.

Cheers,
Tom