Improving GMR Magnetometer Sensor Uncertainty by Implementing an Automatic Procedure for Calibration and Adjustment

Giant Magnetoresistance (GMR) sensors have taken an important role in magnetic field sensing applications thanks to their small size, high sensitivity, large frequency response, low power and relatively low cost. A metrological characterization of a GMR magnetometer has highlighted the contributes to the measurement uncertainty due to hysteresis, non linearity and dependence from temperature. Starting from these knowledge, an automatic procedure for calibration and adjustment of GMR magnetometer has been set up. This procedure, based on a mixed hardware-software solution, allows a deep reduction of the measurement uncertainty for both AC and DC magnetic field strength measurements using GMR.