Multi-parameter sensing technology plays an important role in structural health monitoring. In this paper, a novel FBG sensor with a pendulum structure for simultaneous measurement of tilt and acceleration is proposed. The design, principle and performance of the FBG sensor is introduced and tested in detail. The results show that the tilt sensitivity and acceleration sensitivity of the proposed FBG sensor can reach 408.3 pm/° and 2.43 nm/(m/s2), respectively, and that it works below 32 Hz in weak vibration detection. The theory analysis and the test result are in good agreement with each other. A wavelet transform method is utilized to separate the tilt and acceleration from the original signal received by the proposed FBG sensor. Cross sensitization of tilt and acceleration can be avoided effectively using this method. Finally, a field test is conducted in a railway slope. The recorded data is analyzed, which confirms further that the proposed FBG sensor can detect tilt and acceleration simultaneously. This novel FBG sensor provides a new method for multi-parameter monitoring.

A high precision and small size Fiber Bragg Grating (FBG) inclination sensor which is used for slope monitoring is proposed in this paper. The FBG inclination sensor has a pendulum structure for high precision and a circular body for easy installation in the common inclinometer pipe. The sensitivity of the FBG inclination sensor can reach 400 pm/deg by optimizing its parameters. The test results show the superior performance of this FBG inclination sensor in terms of static characteristics, and its sensitivity is 406.6 pm/deg. The comparison experiment shows the static characteristics of the FBG inclination sensor are better than the traditional electrical inclination sensor.