Tachometer

Contact Tachometers are used to measure the speed of a rotating object in Revolutions Per Minute (RPM). The handheld tachometer couples to the shaft of the rotating component through friction. The tachometer shaft will rotate at the same speed as the component being measured. To measure linear speed such as conveyor belt speed use a contact tachometer with wheel attachment. Place the wheel against the conveyor belt and the wheel will rotate at the same rate. The tachometer will calculate the linear speed on the display based on the rotational rate and fixed diameter of the wheel.

Extech Digital Contact Tachometer

Measures: 
Rotation speed - Surface speed

Large 5 digit LCD display is easy to read • Built-in memory recalls last MAX/MIN value stored. Autoranging with 0.05% accuracy. Contact measurements from 0.5 to 19,999rpm plus linear surface speed measures in ft/min or m/min. Simply contact rotating object with sensor tip and read. Accessory wheels enable tachometer to measure linear surface speeds. See attachments for additional information