Gmi Effects Of Iron-based Longitudinal Research And New Weak Magnetic Sensor

The traditional magnetic devices can not satisfy the requirement of the technology development in sensitivity, measurement range, stability, power consumption and cost, while the novel magnetic sensors based on the Giant Magnetic-Impedance (GMI) effect have the characteristics of miniaturization, high sensitivity, quick response, and low power consumption. Accordingly, the GMI sensor could be widely used in aerospace engineering, traffic control, military detection, mechanical industries (automotive, robotics, materials testing) and so on.In the article, the GMI effect, the production and processing technique of the amorphous materials are introduced. Because the Fe-based amorphous material has a longitudinal magnetic domain, the type longitudinal excitation is selected to design the sensing element. The factors which affect the GMI effect of the sensing elements are analyzed in detail, including the exciting signal, the amorphous material, the stress and the bias magnetic field. Based on the research, two kinds of GMI magnetic sensors, the GMI sensor based on the longitudinal excitation and the differential type GMI sensor, are developed. During the designing, the driving circuits and the conditioning circuits are introduced. Besides, a feedback circuit is added to advance the performance of the GMI magnetic sensor based on the longitudinal excitation.Finally, the characteristics of the GMI magnetic sensors are calibrated, including the static and the dynamic characters. And the experimental results show that the GMI sensors, which can measure the static weak magnetic field ranging from -250uT to 250uT, have characteristics of excellent linearity, low hysteresis, high sensitivity and good repeatability.