The YS-20 Combination Hand-Held Digital Tachometer combines the best features of both contact and non-contact models to accurately measure RPM, surface speed and length.
When using the non-contact mode, rotational speed (RPM) is measured using a visible beam of light. The YS-20 can be up to 14 inches away from the small piece of reflective tape that is affixed to the rotating element. In the contact operating mode, the speed is sensed by directly contacting rotating device using one of the contact adapters supplied with the instrument.
In other applications where surface or linear speeds are to be measured, the universal wheel is used for direct readout of feet/min, meters/min or inches/min, as selected by the end user. The YS-20 can also be used to measure the accumulated total of continuously running material such as paper, wire being wound on a spool, or to check the calibration of on-line counters and totalizers.