Biaxial Optical Accelerometer and High-Angle Inclinometer With Temperature and Cross-Axis Insensitivity

In this paper, we describe the implementation and test of an optical fiber biaxial accelerometer and inclinometer based on fiber Bragg gratings. The proposed sensor is a low cost and simple solution to measure acceleration and relative rotation in two orthogonal directions, which can be used for structural health monitoring. Sensitivities of 87.848 and 92.351 pm.g^-1, for each sensitive direction with resonant frequencies of 846.01 and 845.33 Hz, respectively, are achieved. For the inclinometer, the tilt sensitivities are 1.43 ± 0.03 and 1.38 ± 0.03 pm/o for each orthogonal sensitive direction for angular rotations smaller than 45°. For inclinations higher than 45°, a suitable calibration expression is presented.