HDB-F frequency transmitter adopts new electronic circuit and high stability quartz crystal. It is used to measure the frequency signal and convert it into DC analog signal output. It can measure the frequency of DC signal without auxiliary power. Independently measure AC input signals and pulse input signals; it is used in power and non-power systems where grid frequency needs to be measured. It has a dual output mode for easy control and separate display. The instrument has high measurement accuracy, high resolution, fast response time, and good temperature characteristics.