Optical fiber methane gas sensor based on refractive index change of sensing film
YANG Jian-chun
XU Long-jun
CHEN Wei-min
Abstract：By optical waveguide theory, the sensing principle of optical fiber methane gas sensor based on refractive index change of sensing film was analyzed. The sensor coated with the inclusion of cryptophane A in a transparent polysiloxane film was designed and fabricated. To evaluate its sensing performance and validity, the sensor signal was investigated by means of different concentration methane gas and coal mine gaseous sample. According to numerical simulation result, it is shown that normalized light power of the sensor drops linearly with the increase in refractive index of sensing film from 1.441 to 1. 447. It is suitable for fabricating optical fiber methane sensor with high sensitivity. Analyzed by sensing experimental result, the sensor signal enhances linearly in the methane concentration range of 0～27. 0% ,with slope of 0. 007, which accords with numerical simulation result. The detection limit for methane is 2. 80%, with response time of about 180 s. The sensor indicates good selectivity with almost no interferences from common gases such as CO 、CO_2 、H_2S 、O_2、,N_2. For coal mine gaseous sample ,methane detection result of the sensor agrees with that of gas chromatography,with relative error of 1.47%.
Keywords：optical fiber sensorcryphophane Amethane gassensing filmrefractive index
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 420-423 )