Giant Magnetoimpedance Current Sensor With Spiral Structure Double-Probe

Abstract

A novel giant magnetoimpedance (GMI) noncontact current sensor with spiral structure double-probe is designed. Differing from the formerly reported sensors, the probes of this sensor consist of annealed commercial amorphous ribbons which are curled to spiral tubes. Two couples of permanent magnets are applied to provide bias magnetic field. The distance between the probes and the permanent magnets is fixed at 2.4 cm. The sensor shows sensitivity of 1 V/A in the current range of plusmn1.5 A, measurement precision of less than 0.16% at room temperature, and good thermal stability in the temperature range between -20 and 30degC.