Tri-axis magnetometer with in-plane giant magnetoresistance sensors for compass application

A tri-axis magnetometer comprising three giant-magnetoresistance sensors and a cylindrical fluxguide are implemented for compass application. The sensors are mounted on a single printed circuit board (PCB) board with their sensing axes in a plane. A calibration process involving matrix manipulation was employed to make the device function as a tri-axis magnetometer with orthogonal sensing directions. The capability of the device for compass application was demonstrated by measuring its azimuth response to the geomagnetic field about different rotation axes. The proposed calibration technique can be used for the magnetometer system with either orthogonal or non-orthogonal sensor arrangement. (C) 2015 AIP Publishing LLC.