Frequency counter

Frequency counters usually measure the number of cycles of oscillation or pulses per second in a periodic electronic signal.

Most general-purpose frequency counters will include some form of amplifier, filtering, and shaping circuitry at the input.

Other types of periodic events that are not inherently electronic in nature will need to be converted using some form of transducer.

For example, a mechanical event could be arranged to interrupt a light beam, and the counter made to count the resulting pulses.

A timebase is very delicate, like the hands of a watch, and can be changed by movement, interference, or even drift due to age, meaning it might not "tick" correctly.

A central processing unit (CPU), for example, can be arranged to measure its own frequency of operation, provided it has some reference timebase to compare with.

The resolution of a single count is generally proportional to the timebase oscillator frequency and the gate time.