RPM Counter

Marble Automation developed the MS 921B propeller revolution counter to count the number of revolutions of a propeller or other rotating parts. The LED display clearly shows the number of revolutions per minute. The LEDs also show the direction of revolution of the propeller. The MS 921B can be applied in a wide range of situations. The rpm of a winch, (dredging) pump or bowthruster can all be measured.