Time Division Multiplexing Fibre-Optic Liquid Level Sensors using a Nematic 1x2 Optical Switch

Abstract

In this paper, time division multiplexing with optical switches in a multi-sensor system for level measurements with POF is reported. POF are used in the sensor heads and as transmission media along the optical network. Optoelectronics and electronic circuits are developed to set up the laser output, the light reflected off the liquid surface and the control of the NLC switch. At least two sensor heads are placed in each tank and they are addressed by time division multiplexing using the same laser source. Level measurements on the system integrated by 2 sensor heads in a single tank and a 1x2 optical switch are reported.