Low-frequency temperature compensation fiber Bragg grating accelerometer based on double-arched beam

To address the difficulty of existing optical sensors in meeting the requirements of low-frequency vibration monitoring in large structures, a dual-fiber Bragg grating acceleration sensor based on a double-arched beam was proposed. The difference in a wavelength shift of the two fiber gratings is used as the output signal of the accelerometer to realize the measurement of acceleration and temperature compensation in the low -frequency band. The sensitivity and resonant frequency of the accelerometer were analyzed based on the theoretical model of the sensor, and the sensitivity calibration experiment was carried out. The results show that the resonant frequency of the accelerometer is about 30Hz, the sensitivity is about 1158.6pm/g, and the temperature sensitivity can be reduced to 1.3 pm/C. The accelerometer can be used for real-time monitoring of vibration signals between 0.05 and 20 Hz.