A real time fiber optic micro displacement level sensor

Detection of micro change in liquid level using PMMA fiber in real time is demonstrated in this article. This sensor operates on light intensity modulation and such modulation results due to displacement of a floating reflector. The sensor system consists of light source, encapsulated PMMA fiber, floating reflector, photo detector, transimpedence amplifier, multimeter and a data acquisition system for the static and dynamic measurement. A change of 0.0073V at the output of the transimpedence amplifier was observed for 1 µm change in level. high sensitivity, good linearity, simple design and low cost make this sensor suitable for industry.