Sample Frequency does not matter if it is sufficiently large

1. What happens when the sampling frequency is too high?
2. What happens when the sampling frequency is too low?
3. What determines sampling frequency?
4. How many times sampling frequency should be greater?

What happens when the sampling frequency is too high?

If the rate of samples is too high the system may not be able to process them fast enough - it runs out of processing time.

What happens when the sampling frequency is too low?

As the sampling frequency decreases, the signal separation also decreases. When the sampling frequency drops below the Nyquist rate, the frequencies will crossover and cause aliasing.

What determines sampling frequency?

The sampling frequency or sampling rate, f_s, is the average number of samples obtained in one second, thus f_s = 1/T. Its unit is sample per second or hertz e.g. 48 kHz is 48,000 samples per second. Reconstructing a continuous function from samples is done by interpolation algorithms.

How many times sampling frequency should be greater?

Nyquist's theorem states that a periodic signal must be sampled at more than twice the highest frequency component of the signal. In practice, because of the finite time available, a sample rate somewhat higher than this is necessary. A sample rate of 4 per cycle at oscilloscope bandwidth would be typical.