Prototype of a sensor for simultaneous monitoring of water level and temperature of rivers in the Amazon using FBG

This work proposes an optical fiber sensor capable of simultaneously determining the variation in the level and temperature of the waters of rivers in the Amazon using two in Fibers Bragg Grating (FBG) coupled to a metallic bellows structure, which was experimentally demonstrated in terms of the characterization of FBGs, where one of them is a temperature compensator. The system was simulated according to the Coupled Modes Theory (CMT) and the Transfer Matrix Method (TMM) and experimentally the sensitivity of the sensors was analyzed from the wavelength displacement measurements, simultaneously varying the deformation and temperature. The experimental results show a sensitivity of 9.2 pm/cm and water level measurements up to the limit of 3.95 m with a wavelength variation of 3.69 nm for the strain sensor. The proposed sensor is simple and has enormous potential to be used to monitor the level of rivers in the Amazon in areas at risk of flooding.