Measurement uncertainty of a fibre-optic displacement sensor

Abstract

The measurement uncertainty and linearity of a bundle fibre-optic displacement sensor were studied on a wide range of displacements using experimental and simulation approaches. The theoretical He–Cuomo distribution functions of light intensity yielded the simulated modulation characteristic that best fitted the experimental data in the range of dimensionless distances to the target surface from 0 to 50 but diverged beyond. The coefficient of variation of the output signal of the sensor varied non-monotonically with the distance to the target surface. This variation is suggested to stem from small randomly distributed imperfections on the mirror surface.