AiM 719 Hall Speed Pick Up Sensor (1m cable). The output varies when it meets a magnetic field. The three wire sensor produces a digital signal.

The sensor consists of a thin piece of metal that passes a continuous current through it. When the sensor is placed in a magnetic field the electrons move to one side of the metal and protons move to the other side of the plate. You will then be able to get a voltage.

The sensor only produces around Severn volts. When the electrons move to one side a potential difference id produced between the two sides of metal.

 

Datasheet can be downloaded

Race Studio3 configuration can be downloaded

Race Studio 2 configuration can be downloaded