Study Of High-Precision Magnetic Sensor Base On Amorphous Wire Giant-Magneto-Impedance Effect

The measurement of magnetic field has been application in many technology fields, such as industry, agriculture, national defense, biology and spaceship etc. With the rapid development of science and technology, more demands have been made of the magnetic measurement. In traditional magnetic field sensors, such as Hell sensor, flux gate sensor, there were some flaws and disadvantages, for instance, complicated circuits of the structure, low resolution and limitation of using conditions. For the more researches of giant magneto impedance (GMI) effect, some new magnetic materials, which exhibit better stability, higher sensitivity and quicker response, smaller size appears, provide good conditions for study of new sensors.In this paper, it is analyzed the theory of the Amorphous Wire Giant-Magneto-Impedance (AWGMI) effect and its influence factors in details, and expatiated the sensor principle based on AWGMI. On the basis of AWGMI, the micro-magnetic sensor is designed, which is composed of the driving circuit, data collecting unit, signals detecting unit and processing data circuit. On the basis of micro-magnetic sensor, we design the current sensor. The performances of this kind of micro-magnetic sensor are studied by experiments. The measuring range of the field is±350mGs. The linearity coefficient is 0.9999, the sensitivity is 5mV/mGs, and the resolution is up to 10-9T.In conclusion, it is viable of the technology of the micro-magnetic current sensor based on AWGMI. It needs further improvement on the magnetic shield and software processing.