This sensor is designed for incremental measurement of rotational speed (e.g. camshaft*, crankshaft or wheel speed), but it is not a “true power-on” sensor. Due to the rotation of a ferromagnetic target wheel in front of the HA-D 90, the magnetic field is modulated at the place of the Hall probe. The main feature and benefit of this sensor is a very good detection of the falling edge, due to a differential measuring method. This sensor is a combination of a high quality production part and robust design with a small housing.