In this work is evaluated the performance of etched
fiber Bragg gratings, assembled in different configurations to
operate as a refractometric sensor, in the analysis of water-ethanol
mixtures. Two fiber Bragg gratings operating close to 1300 nm and
1500 nm were wet-etched and employed in the sensor design. Four
configurations for the refractometric sensor were studied, in dualwavelength
and single-wavelength operation modes, and at two
sample temperatures. Calibration curves were determined for the
range between 0.0 and 100.0 % v/v of water in ethanol, and the
sensor performance for each configuration was analyzed by
comparing its sensitivity, conformity, repeatability and combined
uncertainty. The best results showed that the sensor can be used to
measure the ethanol-water concentration with combined
uncertainty of 2.8 % v/v for the range up to 80.0 % v/v of ethanol
concentration and 7.0 % v/v of uncertainty for the range above
80.0 % v/v of ethanol concentration for the single-wavelength
operation mode at two temperatures.
