Here you will find many types of rotation meter. There are different ways of measuring revolutions within the industrial sector, either optically ormechanically. The 151 handheld series of rotation meter with RS-232 interface can measure revolutions and velocity and store the readings onto a computer using software which comes with the device.
The handheld digital rotation meter is ideal for measuring velocity and revolutions in research and maintenance. The T236 rotation meter measures velocity both by contact and non-contact and is good value for money. Non-contact measurement of velocity is done with the help of reflective tape.