Simple Mathematical Operation-Based Calibration Method for Giant Magnetoresistive Current Sensor Applying B-Spline Modeling

Nowadays, giant magnetoresistance (GMR)-based sensor technology is widely used in numerous industrial applications. However, an inexpensive and efficient method for compensating the nonlinear output of GMR spin valve sensors is still under the industrial prospect, which limits the application of the GMR sensors. By applying the B-Spline modeling, excellent results can be achieved; nevertheless, the sensor has to be calibrated in the whole temperature range. In this paper, a simple mathematical operation-based calibration method for GMR spin valve-type current sensors applying B-Spline modeling is introduced. Instead to measure dozens of temperatures and per temperature several hundreds of points, this method allows a calibration for each further sensor applying B-Spline modeling with only two temperatures and per temperature only 15 points. In comparison with the original calibration measurement over temperature for B-Spline modeling, the new calibration with minimized efforts shows outstanding measurement accuracy of ±0.6% at a nominal current of 50 A in a temperature range from -20 °C to 80 °C.