Locating Magnetic Sensor Elements Inside Their Casing

A setup has been developed for determining the axial position of the active magnetic sensor element inside its case with respect to a reference face at the outside of the sensor case. For an axial Hall-sensor providing a sensitivity of 1 mV/muT, an uncertainty in the order of 6 mum is achieved, i.e., the uncertainty of the distance between reference point and Hall element, as specified by the producer, can be reduced by a factor of about 50. For a fluxgate sensor having two rods of 5 mm in length, it is possible to localize its axial magnetic center within nearly the same uncertainty