Amprobe TACH-20 [3311961] Contact and Non-Contact Tachometer The Amprobe TACH-20 Hand-held Tachometer accurately measures rotational or surface speed as well as length. It comes with a large LCD display that allows the user to easily read the measurement. It also has a built in memory function that permits automatic storage of maximum, minimum, average values plus the last measurement displayed. The TACH20 Tachometer is supplied with all the necessary accessories designed with optimal mechanical stability to ensure accurate, reliable, and repeatable measurements. In addition to the mechanical adapter that accepts a variety of tips, as well as the surface speed wheel for contact rpm measurement, the TACH-20 Tachometer can perform non-contact measurement by using the infrared beam function.