Optical Speed Sensors by Monarch are more versatile and application friendly than most speed sensors on the market. These optical sensors are manufactured from threaded stainless steel and feature a visible red LED light source and an "on-target" green LED indicator.

Principles of Operation:

The signal output of a magnetic speed sensor is caused by the excitation of its inductive coil by a passing ferrous target. As a ferrous actuator (speed sensiring gear) moves past the magnetic sensor, the discontinuity in the surface of the gear (i.e. a gear tooth) excites a voltage in the pickup coil, producing an electrical analog wave. The frequency and voltage of the analog signal is proportional to surface velocity of the sensing gear. The operation is similar to an AC Genertor. Each passing discontinuity in the target causes the magnetic sensor to generate a pulse. The cyclical pulse train created by the rotating gear, or a turbine meter blade can be read by varous types of signal conditioners or tachometers.