Honeywell SNDH-H Hall-effect Speed Sensors

The Honeywell SNDH-H Series Hall-effect Speed Sensors use a magnetically biased Hall-effect integrated circuit to accurately sense movement of ferrous metal targets. The specially designed IC (integrated circuit) and a permanent magnet are sealed in rugged, probe-type packages.The flux density of the permanent magnet alters when approached by ferrous metal.

 

This is detected by the Hall ICs. If the sensor is positioned at the circumference of a revolving gear wheel, for example, it detects the teeth and spaces, supplying a digital pulse output with frequency proportional to gear wheel speed. Optimum performance is dependent upon variables that must be considered in combination: target material, geometry and speed, sensor/target gap, and environmental temperature.