Features • Measures speeds from 1-99,999 rpm • Accuracy of 0.02% with a resolution of 0.01 rpm • Easily converts from non-contact to contact operation with a rugged slide-in adapter • Non-contact sensing from up to 14\" • Built-in memory stores maximum, minimum, and last reading for recall to the display","The HH100 is used 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 HH100 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 the 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 HH100 only uses two AA batteries (included) and comes with a NIST Certification at no additional cost. The HH100 uses the latest microprocessor technology and is backed by an industry leading, two-year warranty.