Distributed high temperature sensing using fiber bragg gratings

In this paper we present a novel, practical approach for carrying out distributed high temperature sensing in boilers. We have demonstrated distributed high temperature sensing using fiber Bragg gratings encapsulated inside a rugged mechanical structure. The encapsulation is designed to not only protect the optical fiber from the harsh environment of the boiler, but also to scale the temperature down to a range over which the gratings are relatively stable. A key aspect of our work is the use of a Bayesian inference technique to retrieve the temperature outside the encapsulation within < 1°C accuracy based on the temperature measured by the fiber Bragg grating (FBG).