Monitor light water concentration in deuterium oxide by evanescent absorption sensor

The feasibility of coiled optical sapphire fiber sensors based on evanescent absorption spectroscopy in the infrared range for the quantitative determination of H2O content in deuterium oxide has been investigated. The coiled optical fiber sensor based on evanescent absorption spectroscopy centered at 2.9 μm has been applied to implement for the in situ monitoring of H2O concentration in deuterium oxide. The classical least square model has been utilized to build the calibration model and predict the H2O concentrations. The predicted H2O concentration in deuterium oxide is acceptably accurate and susceptible. The study demonstrates that the coiled fiber-optic sensor based on evanescent absorption spectroscopy is a feasible analytical technique for prediction of the low-level H2O content during deuterium oxide distillation in on-line and remote situation.