A magnetic field sensor based on flaky Terfenol-D material and dual fiber grating

Magnetic field measurement has a wide range of applications in many fields such as safety production, disaster prevention and mitigation, and geological exploration. Aiming at the problems of low sensitivity and temperature cross-sensitivity of fiber optic magnetic field sensors, a magnetic field sensor based on flaky Terfenol-D material and dual fiber Bragg grating is proposed. First, the sensor model is established using SolidWorks, and the strain transfer theory is analyzed. Second, the flaky Terfenol-D material is prestressed to optimize the performance of the sensor. Finally, the sensor is developed, and a magnetic field test system is built for performance testing. Experiments show that the magnetic field sensitivity of the sensor is 53.44 pm/mT, the resolution is 37.4 μT, and the temperature sensitivity is 0.23 pm/°C under an optimal prestress condition of 3.5 MPa, and the directivity is in line with the cosine law. The temperature decoupling method of dual fiber differential is used to compensate the temperature of the sensor and correct the magnetic field measurement results, which effectively suppresses the temperature interference and improves the accuracy of the magnetic field measurement. The research results are expected to be applied to magnetic field measurements in harsh environments such as complex electromagnetic interference.