Study of an Electro-Optic Technique of Level Transmitter Using Mach-Zehnder Interferometer and Float as Primary Sensing Elements

Measurement of liquid level in a storage tank using float is one of the important, simplest and cheapest method. However, the main drawback of this sensor is its inability to transmit the reading. Costlier and complicated designs are developed to transmit the float position to a remote station like control room. Direct transmission of electrical signal through connecting wires is generally prohibited in the inflammable region. In this paper, a very simple electro-optic system has been developed to transmit the electrical signal output of the transducer to a remote location using Mach-Zehnder interferometer. The necessary equations describing the principle of operation of the proposed transmitter are derived and presented in this paper. The operation of the transmitter is experimentally tested, and the experimental results are reported in this paper. A very good linearity and repeatability of the transducer and transmitter characteristics have been observed.