FBG センサによる高温環境下原子炉配管変形計測用 歪み・温度モニタリング技術の開発
Development of the FBG sensor for strain and temperature monitoring of high-temperature pipelines of nuclear power reactors
小林 喬郎 Takao KOBAYASHI 猿田 晃一 Koichi SARUTA 福元 謙一 Ken-ichi FUKUMOTO
fiber Bragg grating (FBG) sensor high speed strain measurement on-line monitoring method optical fiber strain gauge
Abstract : A new technique of temperature and strain measurement using fiber Bragg grating (FBG) optical fiber sensor at high temperature in irradiation environment was proposed, in which interrogation of FBGs is carried out based on optical time-domain reflectometry (OTDR). Heating test results showed that stable temperature measurement can be done at 600°C and the reflectance of FBG can be kept constant up to 1000°C. From the strain measurement test on a cantilever, multi-point strain measurement capability with high measurement accuracy was successfully demonstrated. Strain distribution mapping of a compressed elbow pipe and an observation of damping oscillation of a cantilever are also presented as practical applications of our technique. The FBG-OTDR optical fiber sensor will be a promising tool for inspection and diagnostics of material degradation in nuclear engineering applications.