UT370 series photoelectric digital tachometeris of stable performance, safe and reliable. The device circuit design takes the single chip as the core.  The photo electric revolving speed sampling & processing and unique appearance design make the device become the tachometer with excellent performance. The tachometer can be used for revolving speed measurement and count. The revolving speed range is from 10 to 99999 r/min. The count range is 0～99999. It is applicable to school, factory, environmental protection agency, lab, research institution and automobile maintenance testing and so on.