开环式GMR传感器电流测量实验研究

Experimental study on current measurement using open-loop GMR sensor

利用巨磁电阻搭建惠斯通电桥,电阻构成的平面与磁敏电阻二维膜平面平行,改变待测电流与二维膜面的距离和夹角,调整待测电流与电桥磁敏感轴的夹角,选用恰当的电桥输出电压测量仪器对GMR电流传感器的线性度进行分析,发现开环结构的GMR电流传感器的线性拟合优度在mA^A级别达0.999以上.由于GMR电流传感器对弱磁场能产生响应,环境磁场对测量结果会产生影响,实验以磁电式电表为影响源从磁滞的角度对该问题进行了分析.

A Wheatstone bridge was built with the plane of the bridge resistors parallel to the twodimensional film surface of the magnetic resistor.By changing the distance and angle between the current and the two-dimensional film surface,adjusting the angle between the current and the magnetic sensitive axis of the bridge,selecting the appropriate bridge output voltage,the linearity analysis of the GMR current sensor were realized.The linear degree of the GMR current sensor with open-loop structure was found to be above 0.999 in the range of milliampere to ampere.As the GMR current sensor could respond to weak magnetic field,the environmental magnetic field would have an impact on the measurement results.Using the magnetic-electric meter as the source of influence,the problem was analyzed from the viewpoint of magnetic hysteresis.