Study of new giant magneto-impedance sensor

In a non-linear non-diagonal GMI sensor for weak magnetic field, the pickup coil parameters, including the length, the diameter of coil tube, the number of turns as well as the diameter of the coil wire, in relation to the sensor sensitivity are investigated. The results showed that the sensitivity is directly proportional to the ac driving frequency, and the number of turn density of the pick-up coil. With smaller wire diameter and smaller coil diameter, the sensor sensitivity improves. With a 1 000 turns coil, a sensitivity of 3. 518×10^-2V/Am^-1 was achieved in the testing range of ±400 A/m. Its resolution is up to 10^-7A/m and can be worked up to 150°C. This shows great potential for weak magnetic field detection and other applications. The experimental results are explained, taking account for Faraday inductive law and coil parameters.