Realization of simultaneous strain and temperature measurement using FBG

Abstract

Fiber grating works as a novel kind of smart sensing element. It adopts wavelength encoding. It is prone to multi-points multiplexing and it is compatible with normal fiber system completely. It has been got extensive and deeply research in fiber sensing field because such advantages. In order to realize simultaneous strain and temperature measurement, solving temperature and strain's cross sensitivity is the key problem in fiber grating sensors researching. Simultaneous strain and temperature measurement using fiber Bragg grating(FBG) is presented in this paper. Different cladding diameter fiber solve temperature and strain's cross sensitivity problem. Demodulation system adopts arrayed-waveguide grating (AWG). It has merits of high wavelength resolution, integrated, small series-mode interference and low insertion loss. Light source adopted clock pulse broadband source. The system integrates time division multiplexing and wavelength division multiplexing to solve the multiplexing addressing problem of FBG sensing network. It proved feasibly according theoretical analyzing. Measuring strain range from 0 to 2500 μe. Measuring temperature range from 25 to 120°. Error of strain is ± 17 μe and error of temperature is ±1°C.