The 505L is a combination photo and contact tachometer that also measures surface speeds of belts and wheels.

Measure motor input and output shaft speed Determine conveyor belt speed Confirm fan, motor, and gear RPM Measure RPM of flywheels and pumps Monitor pulley rotation RPM and turbine speeds Mutifunctions : Photo Tach & Contact Tach & Surface Speed Wide Measuring Range: 6 to 30,000 RPM Last Value, Max Value, Min Value: Automatically Saved and Recalled