A simple underground liquid level sensor using FBG

Abstract

In this paper a packaged sensor using fiber Bragg grating for under water level measurement is presented. The sensor is configured by fixing one end of a fiber Bragg grating with a diaphragm made up of polymer kept inside a hollow cylinder and the other end to the cylinder. As the level of water increases in the tank hydrostatic pressure at the bottom also increases. The diaphragm used in is to transfer this pressure to the axial strain on the grating. By utilizing the unique diaphragm‐based grating packaging method, the level sensing range has been effectively enhanced. The results obtained indicate that this packaged sensor have long range, rugged and can be customized depending on the requirement. The sensitivity of the sensor is within the range 0 to 30 cm.