Improving Performance of GMR Sensors

Giant magnetoresistance (GMR) sensors are assumed as an important role in magnetic field sensing applications because of their small size, high sensitivity, large frequency response, low power consumption, and relatively low cost. In all these applications, it is very important to estimate and possibly reduce the measurement uncertainty related to the use of these sensors. In this paper, the metrological characterization of GMR magnetometers highlights the contributions to measurement uncertainty of hysteresis, nonlinearity, and operating temperature. Starting from this knowledge, an automatic procedure for calibration and adjustment of GMR magnetometers is setup. This procedure, based on a mixed hardware-software solution, allows a meaningful reduction of the measurement uncertainty for both ac and dc magnetic field amplitude measurements using GMRs.