Extech 461891 Contact Tachometer

First, a small piece of reflective tape (approximately 1/4-inch) is mounted on the object to be measured. Second, the light beam or laser is pointed at the revolving tape. The reflection from the tape provides a reading to be displayed and updated once per second. For the most accurate measurements, the distance between the tachometer and the reflective tape should be within 6 inches for a light beam and up to 6.5 feet for a laser. Fluorescent or bright ambient lights may interfere with the measurement.

Make non-contact RPM measurements (5 to 99,999 rpm) of rotating objects by pointing the integral light beam (6 inch target distance) at the reflective tape placed on the object to be measured. The memory button holds last reading and recalls min/max readings display. Complete with four AA batteries, 23 inches (0.6 meter) reflective tape, and carrying case. Also available: Reflective Tape for Photo Tachometers (461937) for use with any brand photo tachometer. Place a piece of reflective tape on the object to be measured and point the tachometer's integral light beam at it. Ten reflective tape strips. Each strip measures 23 x 0.25 inches (584 x 6 mm).