Non-contact salinity measurement using a bifurcated fiber bundle sensing

Abstract

A non-contact salinity sensor using a bifurcated fiber bundle sensing is proposed. The sensor was operated based on intensity modulation due to the variation of displacement between the tip of the probe with the surface of the sample. The light that reflected back into the receiving fiber bundle is analysed and correlation with the salinity of the samples has been performed. This allows the performance of the sensor towards salinity to be quantified based on the front slope, back slope and peak intensity. The proposed configuration has been calibrated and then experimentally validated. The calibration curve can be plotted based on three parameters: peak intensity, front slope and back slope. The peak intensity curve exhibits the highest sensitivity of 1.52×105 a.u./M with the resolution of 4.2×10-2 M. The ubiquitousness of sensor configuration and non-contact measurement make the proposed sensor a viable alternative to standard commercial devices.