Novel Magnetic Field Meter Based on Giant Magneto-impedance (GMI) Effect

Abstract

A novel magnetic field GMI-sensor/meter has been invented and designed. Its laboratory model was constructed and tested, demonstrating the sensitivity of 1.10–8 T (100 mGs). The principle of operation of this meter is based on changes of the quality factor of the resonance circuit a part of which is a magnetic GMI sensing element.These changes are due to variations in the real component of the impedance of this element caused by an external DC-field. The sensing element is in the form of a piece of the “non-magnetostrictive” amorphous ribbon. Magnetic field modulation of an acoustic frequency and feedback circuit (compensating field) applied to the device, significantly increases stability and linearity of the measuring system.

Keywords

• magnetic field sensor
• giant magneto-impedance
• metallic glass