Novel tilt measurement method based on self-demodulated FBG sensor and pendulum clinometer

A novel tilt measurement method is proposed based on self-demodulated fiber Bragg grating (FBG) sensor system, which consists of a couple of matched FBGs and a cantilever-based pendulum clinometer. With a cantilever structure, the tilt angle is measured by means of a differential form of Bragg wavelength shifting, with which the cross-sensitivity of temperature is eliminated simultaneously. It has been proved by both simulations and preliminary experimental results that a high resolution better than 0.0022 degree can be achieved in the range of +/-10 degrees.