Electronic counters can be divided into 4 categories by function:
① Universal counter: measurable frequency, period, multi-period average, time interval, frequency ratio and accumulation.
②Frequency counter: a counter specially used for measuring high frequency and microwave frequency.
③ Calculation counter: a counter with a calculation function, which can perform mathematical operations, and can use program control to perform all calculations such as measurement calculation and display.
④Microwave counter: a microwave frequency meter composed of a general counter and a frequency counter and a frequency measuring expander. Its frequency measurement upper limit has entered the millimeter wave band, and there are three types of manual, semi-automatic and automatic. Serialized microwave counters are an important aspect of the development of electronic counters.