In the present work we report on the development of a low cost interrogation system of
fiber Bragg grating sensors for structural health monitoring. The developed scheme uses two
gratings and a directional coupler as sensing point, and it includes self-compensation of temperature
effects. The reading equipment consists of a standard photodiode for telecom applications with
custom signal-conditioning electronics. The characterization of multiplexed sensors, carried out in
real framework conditions, shows that the system can work in a temperature range of -20÷+40°C,
making strain measurements up to at least 320με with an accuracy of ~3% and an acquisition rate of
12 samples/min. Further, a budget evaluation is drawn to asses the feasibility of our interrogation
system as a low cost solution to increase the extent of structural health monitoring in funds-limited
applications.
Study on fiber-optic low-coherence interferometric and fiber Bragg grating sensors