Surface wheels measure contact surface speeds (10 to 9,999 rpm) of rotating objects. The memory button holds last reading and recalls min/max readings display. Complete with wheels for linear surface speed (0.2 to 6560 feet/minute; 0.05 to 1999.9 meters/minute) or RPM measurements.
What's in the Box
Comes with cone tip, flat tip and spare wheel for surface speed measurements, four AA batteries, carrying case, and user manual.
Motor speed, moving fans, pumps, and gears, propeller devices, and many other general maintenance, production, and automotive uses.
What is a Tachometer?
A tachometer is a device that measures the angular speed of a rotating shaft in terms of revolutions per minute (RPM). Also, a tachometer can measure linear speed in terms of feet per minute (feet/minute) or meters per minute.
How do Contact Tachometers Operate?
The sensor tip is placed in direct contact with the rotating object. After 2 seconds an accurate reading is displayed. Linear surface speed can also be measured by placing the edge of the wheel on the moving object.
How do Photo (Non-contact) Tachometers Operate?
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.
Range: 0.5 to 19,999rpm/ 0.2 to 6560ft/min/ 0.05 to 1999.9m/min
Accuracy ±(0.05%rdg +1d)
Sampling Time 1sec>6rpm
Resolution 0.1rpm (0.5 to 999.9rpm);1rpm >1000rpm
Dimensions 6.7 x 2.8 x 1.5" (170 x 27 x 37mm)
Weight 9.2oz (260g)
Extech 461891 Contact Tachometer Fast and Accurate RPM With Surface Speed Measurements