Abstract:In order to meet the needs of metering the dry mixtures and finished explosive for explosive mixing truck,we have developed an electric pulse tachometer which can transfer the conveyed amount of mixtures into electric signals of rotational speed to achieve the aim of metering.This paper expounded the work principle and the structure of sensor, and the design of rotational speed-converted circuit for this tachometer, briefly introduced its application and the expansion of the functions of the instrument.