Question

what is the minimum sampling rate needed in order to succesfully capture frequency up to 155 KHz in an analog signal?

Answer 1

Answer:

Due to the Nyquist rate, you need to sample twice as fast as the highest frequency you want to measure. Then when you do a FFT the number of samples determines the number of bins and thus the frequency resolution.

But what about the lowest frequency you want to measure? I would think your sampling duration needs to be at least as long as one cycle of your lowest frequency.