Sensing of hydrostatic pressure using FBG sensor for liquid level measurement

Abstract

Pressure and temperature are two important parameters in hydrostatic pressure based liquid level sensing. In this study, we propose a liquid level sensor based on hydrostatic pressure variation sensed by fiber Bragg grating (FBG1) attached to a bourdon tube. The water column pressure sensitivity coefficient of FBG1 is 0.072 nm/m. One more FBG2 is incorporated to avoid cross sensitivity of temperature. The temperature sensitivity coefficient of the FBG1 and FBG2 are 10.5 pm/°C and 10.2 pm/°C. The packaged sensor head can be placed inside a chamber and also easily mountable external to the tank for the measurement of liquid level.