Investigation on high temperature characteristics of FBG sensors

摘要

In some extremely severe environments, such as aero engine and oil well, the pure fiber sensor cannot meet the requirement of the high temperature. In this paper, temperature model of the fiber gratings sensor and the heat deterioration theory under high temperature are studied, the experiment tested the 2 relationships: (1) between the reflectance of the fiber gratings and the temperature; (2) between the wavelength of fiber gratings and the high temperature. The result showed, the reflectance of fiber gratings with germanium-doped was decreased gradually when the temperature was increased. When the temperature reached to 850 degrees C, the fiber grating was failed. Under the 850 degrees C, the degree of linearity fitting between the central reflective wavelength of fiber gratings and the increasing temperature became worse, while the temperature sensitivity decreased with temperature increasing. The average temperature sensitivity of gilded germanium-doped fiber grating sensor was 0.0156 nm/degrees C and has been improved greatly compared with the pure fiber grating. (C) 2015 Elsevier GmbH. All rights reserved.