Tachometers - Speedometers

The handheld tachometer/speedometer is an instrument for measuring the rotational speed of shafts, operating optically or mechanically. Tachometers, also known as speedometers, are widely used for the maintenance and calibration of machines with moving parts.

Their operating principle is similar to a bicycle speedometer, where time is measured until the wheel completes one full rotation. Tachometers have two different measurement methods. One is by contact with moving parts, either with a cone or with a pulley. Alternatively, they operate optically - laser - in combination with reflectors, which are self-adhesive and placed on the shaft to be measured. As the laser hits the reflective mark during rotation, it will be reflected and detected by the tachometer. The instrument displays the rotational speed. Finally, there are tachometers that operate both with laser and with contact. This last category additionally has the capability to measure linear speed and linear distance.

For companies that wish to include a handheld tachometer for internal use, the calibration process is recommended.