%A Shaomin LI, Xiaoying LIU, Chong LIU %T FBG sensing temperature characteristic and application in oil/gas down-hole measurement %0 Journal Article %D 2009 %J Front. Optoelectron. %J Frontiers of Optoelectronics %@ 2095-2759 %R 10.1007/s12200-009-0042-8 %P 233-238 %V 2 %N 2 %U {https://journal.hep.com.cn/foe/EN/10.1007/s12200-009-0042-8 %8 2009-06-05 %X

Fiber Bragg gratings (FBGs) have been used to sense numerous parameters such as strain, temperature, and pressure. Cost-effective multipoint measurements have been achieved by connecting FBGs in parallel, serial, and other topologies as well as by using spatial, wavelength, and time-domain multiplexing techniques. This paper presents a method of measuring temperature of the oil/gas down-hole. Detailed contents include the basic theory and characteristics of fiber gratings, analysis of the sensing mechanism of fiber-optic gratings, and the cross-sensitivity effect between temperature and strain; the method of making the light-source of the fiber-optic gratings and the technology of measuring wavelength shift, building an experimental system of the temperature measurement, and dealing with the experimental data. The paper makes a comparison of several kinds of FBG sensing systems used in oil/gas down-hole to measure temperature and the analysis of the experimental results of building the temperature measurement system. It demonstrates that the fiber-optic grating sensing method is the best choice in all methods of measuring temperature in oil/gas down-hole, which has a brilliant applied prospect.