Temperature-Compensated Magnetostrictive Current Sensor Based on the Configuration of Dual Fiber Bragg Gratings

Abstract

For the optical current sensor that combines FBG and magnetostrictive material, a key problem is that the performance of FBG and magnetostrictive material is influenced by the operating temperature. In this paper, in order to overcome this problem, we proposed a method of temperature compensation based on the dual FBG configuration, which can make the measuring result of magnetic field be essentially temperature independent. In this method, two FBGs with the same type are bonded on two giant magnetostrictive materials, respectively. The two giant magnetostrictive materials have the identical shape and come from the same bulk material, while they have the orthogonal magnetostriction directions. We perform the experiment to investigate the performance of this method at different temperatures and at different magnetic fields, in order to verify the feasibility of this method. The experiment results demonstrate that this method significantly decreases the influence of temperature, and thus it can maintain a relative good performance in the temperature range of 20 °C–70 °C.