COMPARATIVE STUDY OF STRUCTURES TEMPERATURE MONITORING USING FBG ARRAY AND DISTRIBUTED SENSING IN REAL TIME
The present study aims to characterize the spectral parameters of optical fibers and single mode optical fiber sensors as well as to highlight two complementary methods of measurement: one based on the variation of the central wavelength of FBGs (Fiber Bragg Gratings) that are located in fixed positions within the fiber and the other based on Optical Frequency Domain Reflectometry (OFDR). The results may provide complex information in the case of a structure that is monitored. The distributed sensor method provides the temperature and mechanical stress variations throughout the fiber length. At some points inside a thermally controlled chamber, we found that the temperature differs due to its uneven distribution. Optical fibers calibration and measurements were carried out in the Photonics Investigation Laboratory (CETAL, NILPRP) through various assemblies and configurations in the spectral range 800-1670 nm.