Extech rpm33 combination contact and laser phototachometer extech rpm33 the extech rpm33 combination contact laser photo tachometer allows you to quickly measure rpm surface speed and length with one tool use the contact wheel for up close readings or laser mode for safer non contact measurements up to 500mm 1 6ft away contact rpm applications include measurments on flywheels conveyors pumps and lifts non contact rpm applications include measurements on motors fans and gears the ta