Dual-parameter sensing characteristics of a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing

Abstract

A novel technology for the simultaneous and independent measurement of dual parameters is proposed and experimented. By using a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing conditions, the sensor structure is designed such that the reflective single-peak spectrum splits into a twin-peak spectrum, which makes the FBG spectrum form a natural spectral peak splitting bias. A measurement limitation exists in the FBG sensor packaging at room temperature, which can be solved by the high-temperature cured packaging method. To verify the validity of the theory and methodology, the experimental system is used. In the range from –1000 to +1000 με and from 35 to 75°C, the Bragg wavelength change is relative linear to the strain and temperature. The temperature and strain variations can be independently and simultaneously measured using the split peak, and the deviations of the FBG sensor are ±1°C and ±5 με, respectively. This single FBG sensor can realize dual-parameter measurement, which is valuable for narrow-space health monitoring.