A novel FBG-based accelerometer with high sensitivity and temperature self-compensation

Sensing techniques based on Optical Fiber Bragg Grating (FBG) has been increasingly applied in civil engineering structures. However, it is still lacking of a reliable FBG based accelerometer for structural vibration measurement. In this study, a novel FBG accelerometer was developed. The developed sensor has high sensitivity for acceleration measurement especially in low frequency range where the natural modes of civil engineering structures are usually concerned. Furthermore, the temperature influence can be self-compensated. This paper described the principle of the sensor and the parameter optimization for improving the sensor's sensitivity in its measurement ranges of magnitude and frequency. A prototype sensor was manufactured; the optimal viscosity of the damping liquid filled in the sensor was selected experimentally. The amplitude-frequency relationship, the sensitivity and the linearity of the sensor were gained through calibration tests. The results of the tests showed that the feasibility of the FBG accelerometer developed are satisfactory for low frequency vibration measurement.