Electronic – How to figure out SNR of a transducer

transducer

This is a novice question.

There is an accelerometer which outputs -10 to +10V voltage output.
If I sample the output for constant output(accelerometer is not moving), can I say anything about signal to noise ratio by looking at samples? What should be the method to investigate SNR here or impossible?

Best Answer

If I sample the output for constant output(accelerometer is not moving), can I say anything about signal to noise ratio by looking at samples?

You can only say what the noise is. Here's how you compute the noise RMS level based on taking many samples: -

enter image description here

Picture taken from here.

Subtract your static DC offset from the noise samples before squaring each term. Alternatively, if your noise is gaussian in nature you can estimate the RMS value from the peak values: -

enter image description here

A reasonable approximation would divide the p-p value by 6.6 to get RMS. Picture directly above taken from here. Here's a picture from TI that shows the reverse calculation: -

enter image description here

Regarding your signal, if you know what performance your transducer gives i.e. its transfer function then you can assume that a signal is present in the noise you have measured and calculate SNR.

Related Topic