Fig. 1. Structure of the FBG sensor

Fig. 2. Principle of the FBG sensor

Fig. 3. Inclinometer principle of the FBG sensor

Fig. 4. Schematic diagram of the FBG inclinometer sensor and package structure

Fig. 5. Physical image of the FBG inclinometer sensor. (a) Main part; (b) shell part

Fig. 6. Calibration experiment device of the FBG inclinometer sensor

Fig. 7. FBG sensor wavelength change curve with time. (a) FBG1; (b) FBG2

Fig. 8. Change curve of wavelength difference with time

Fig. 9. Change curve of wavelength ratio difference with tilt angle

Fig. 10. Comparison of actual and theoretical calculation values

Fig. 11. Slope model and sensor layout. (a) Layout of the sensors; (b) physical object of the slope model

Fig. 12. Change curve of the tilt angle of the FBG inclinometer with time

Fig. 13. Displacement relationship curves between FBG inclinometer and LVDT displacement meter