Mobile ions generated by external direct current electric field influence direct current measurement of giant magnetoresistance current sensors

Abstract

The application of giant magnetoresistance (GMR) current sensors in power grid and other industrial fields has a great prospect benefitting from their wide bands, high sensitivity, and good linearity. This paper studies the influence of mobile ions on current measurement of GMR sensor under high external electric field. The R-H curves of GMR multilayer sensor were depicted when the external electric and magnetic fields were both changed under three orthogonal electric field orientations. The experiment results indicate slightly varying resistances of GMR sensor when the external electric field was changed, and simulation analysis reveals that the resistance variation is attributed to the movement of surface ions under high external electric field. Therefore, a Faraday box is essential for GMR sensors to avoid interferences under high-strength field conditions, which is especially significant for their application as current sensors of the power grid.