The multi-point strain measurement is necessary to monitor the structural health status. For this purpose, the Fiber Bragg Grating sensor system was constructed. This FBG sensor system used a scanning Fiber Fabry-Perot filter as a demodulator. Real-time signal processing program was constructed to monitor FBG sensor system. To assure the operation of the FBG sensor system, the tensile test was performed. In the tensile test, two FBG sensors were attatched to the surface of graphite/epoxy laminates to measure the strain in composites. The strain measured by the FBG sensor was compared with that by the resistance strain gage. Experiments showed that the constructed FBG sensor system and the real-time signal processing program could successfully interrogate wavelength division multiplexed FBG sensors and measure the structural strain.
