Optical Fiber Grating Temperature Sensor Resistance Strain Crosstalk Design And Experimental Research

As a novel fiber optic sensor, fiber Bragg grating sensor utilizes the property that theBragg wavelength is sensitive to temperature and strain. Compared with traditionalelectrical sensors，it has undeniable superiorities such as compact size，small mass，immune to electromagnetic interference， easy to multiplex， etc.Owing to theseadvantages，Optical fiber Bragg grating has increasingly application in many fields suchas large scale structure，electric power，security，petrochemical，medicine，mine andmilitary. Among them, the fiber Bragg grating temperature sensor used in the longdistance temperature measurement system is the most attractive one. As China carriesout the strategy of promoting the internet of things’ development, optical fiber sensorresearch and industrialization are facing great opportunities and challenges.This paper mainly discusses the principle of the fiber Bragg grating temperaturesensor，the structure design for strain crosstalk resistance，the process of sensorencapsulation and experimental research, in the end, the application of the fiber Bragggrating temperature sensor in the temperature measurement system is present.Firstly, this paper introduces the general situation of the optical fiber sensor and theapplication fields of the optical fiber sensing technology. Then based on this，theclassification of the optical fiber sensor is referred，which includes functional sensorsand nonfunctional sensors and pickup light sensors.Secondly，this paper expounds the fabrication process of high-temperature fibergratings and analyzes the theoretical model of fiber gratings and fiber Bragg gratingtemperature sensors’ sensing principle. And then, this paper analyzes the influence ofthe Strain crosstalk on fiber grating temperature sensors and demonstrates the necessityof resolving the problem of cross-sensitivity between temperature and strain.Moreover，this article refers to a host of literatures，patents and summarizes thecurrent major encapsulation methods for fiber Bragg grating temperature sensors andthen proposes a new fiber Bragg grating temperature sensor which is designed notsensitive to the strain，including the structure of sensors，materials，and sealingtechnology. Aiming at the fiber Bragg grating temperature sensor, a lot of experiments of temperature and strain were done in this paper.The last but not the least，the paper introduces the application of the fiber Bragggrating temperature sensor in the Optical fiber temperature fire alarm system, then adetailed instruction is made for software and hardware of the whole system. Hardwareincludes the central processing and control platform，demodulation devices of sensingsignal and optical fiber Bragg grating temperature sensors; function of the softwareincludes sound and light alarm and position shows, monitoring data, real-time storage ofalarm log and so on.