Low Cross Sensitivity and Temperature Compensation Fiber Bragg Grating Accelerometer Based on Miniature Slide Rail

Abstract

In order to meet the needs of accelerometers in vibration monitoring, a fiber Bragg grating (FBG) accelerometer based on a miniature slide rail is proposed. The accelerometer consists of two FBGs, a miniature slide rail, two spring plungers, and a mass block. Since the motion of the two fiber gratings is in opposite directions, the induced displacement of the center wavelength can wipe one another out. So, the effect of temperature can be reduced and the sensitivity of the fiber grating can be improved. Through theoretical analysis and experimental verification, the resonant frequency, sensitivity, and lateral immunity of the sensor are studied. The experimental results show that the effect of temperature on the sensor structure is reduced to 0.3 pm/°C in the range of 22.5 °C–90 °C. The resonant frequency of the accelerometer is 200 Hz, and the FBG accelerometer has a broad frequency range from 0.5 to 150 Hz, with a corresponding sensitivity range from 307.3 to 319.2 pm/g, and the lateral immunity is less than 0.5%. The sensor is simple in structure and easy to manufacture. Therefore, it has great prospects for application in structural health monitoring and other fields.