Performance of a new bundle fiber sensor of 1000 RF in comparison with 16 RF probe

The comparison of bundle sensor performance between 16 concentric receiving fiber (RF) and 1000 hemicircular RF probes is reported. A theoretical analysis is developed for 1000 RF to support the experimental findings, which uses an electromagnetic Gaussian beam approach to determine the transfer function of the probe. Three linear ranges of the displacement profile can be obtained from each probe, namely, the front slope, the first back slope, and the second back slope. The highest sensitivity obtained by the 16 concentric RF at the front slope range is 5.8148 mV/mm with a resolution > 0.3μm. Its lowest sensitivity at the second back slope region is 0.06 mV/mm with an initial resolution of 26. The 16 RF probe produces a better sensor performance both at the front slope and the first back slope region, whereas at the second back slope region, the 1000 RF exhibits a higher sensitivity. Furthermore, a wider linear range is realized through the 1000 RF whereby the front slope and the first back slope are 1.45 and 4.75 mm, respectively. The second back slope of the 16 RF, however, provides a longer linear range 3.0 mm. The latter sensor probe has many potential applications in the longer displacement range, such as position control, micro-displacement sensing in hazardous regions, and automated monitoring control.