Wang Shutao, Wang Changbing, Pan Zhao, et al. Applications of optical technology in gas concentration detection[J]. Opto-Electronic Engineering, 2017, 44(9): 862-871. doi: 10.3969/j.issn.1003-501X.2017.09.002
Citation: Wang Shutao, Wang Changbing, Pan Zhao, et al. Applications of optical technology in gas concentration detection[J]. Opto-Electronic Engineering, 2017, 44(9): 862-871. doi: 10.3969/j.issn.1003-501X.2017.09.002

Applications of optical technology in gas concentration detection

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  • Seven common optical methods for gas concentration detection are described. The basic principles, advantages and disadvantages of each method are given in detail. The improvement work and some novel ideas are presented. The applications of combined methods are discussed. These optical methods include some conventional gas concentration detection technologies, such as optical interferential method, photoacoustic detection (PAS), correlation spectroscopy, and some novel gas concentration detection technologies, such as tunable diode laser absorption spectroscopy (TDLAS), evanescent wave field sensing technology, hollow core photonic bandgap fiber (HC-PBF) sensing technology and fiber loop ring-down spectroscopy (FLRDS). The prospect of optical gas sensing is listed at the end of the paper, which mainly refers to miniaturization, intelligence, portability, low power consumption, high accuracy, fast response and distributed multi-component telemetry technology.
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  • [1] 褚衍平. 基于谐波检测原理的双光路光纤气体传感系统研究[D]. 秦皇岛: 燕山大学, 2009.

    Google Scholar

    Chu Yanping. Research on two optical paths fiber gas sensor based on harmonic detection[D]. Qinhuangdao: Yanshan University, 2009.http://cdmd.cnki.com.cn/Article/CDMD-10216-2010018304.htm

    Google Scholar

    [2] 侯伟. 基于谐波检测技术的气体浓度测量方法研究[D]. 沈阳: 东北大学, 2013.

    Google Scholar

    Hou Wei. Research on gas concentration measuring method based on harmonic detection technology[D]. Shenyang: Northeastern University, 2013.http://www.wanfangdata.com.cn/details/detail.do?_type=degree&id=Y2994782

    Google Scholar

    [3] 杨开武, 白鹏, 陈长兴.气体浓度光学分析方法研究[J].煤气与热力, 2007, 27(8): 17–21.

    Google Scholar

    Yang Kaiwu, Bai Peng, Chen Changxing. Study on optical analysis method of gas concentration[J].Gas & Heat, 2007, 27(8): 17–21.

    Google Scholar

    [4] 郑龙江, 李鹏, 秦瑞峰, 等.气体浓度检测光学技术的研究现状和发展趋势[J].激光与光电子学进展, 2008, 45(8): 24–32.

    Google Scholar

    Zheng Longjiang, Li Peng, Qin Ruifeng, et al. Research situation and developing tendency for optical measurement technology of gas density[J]. Laser & Optoelectronics Progress, 2008, 45(8): 24–32.

    Google Scholar

    [5] 鲜跃仲, 薛建, 张文, 等.新型二氧化硫气体电化学传感器的研究[J].高等学校化学学报, 2000, 21(9): 1375–1376.

    Google Scholar

    Xian Yuezhong, Xue Jian, Zhang Wen, et al. Studies on a novel sulfur dioxide gas electrochemical sensor[J]. Chemical Journal of Chinese Universities, 2000, 21(9): 1375–1376.

    Google Scholar

    [6] 宋林丽, 张志杰, 刘子健.基于催化燃烧原理的新型瓦斯检测系统研究[J].中北大学学报(自然科学版), 2015, 36(3): 372–377.

    Google Scholar

    Song Linli, Zhang Zhijie, Liu Zijian. A novel mashgas detection system based on catalytic combustion principle[J]. Journal of North University of China (Natural Science Edition), 2015, 36(3): 372–377.

    Google Scholar

    [7] 王秀敏.用气相色谱法测可燃气体浓度[J].中国科技纵横, 2010(9): 113.

    Google Scholar

    [8] 陈国华, 兰晓峰, 李发旺, 等.气相色谱法定量分析气体中二氧化硫[J].内蒙古石油化工, 2009, 35(1): 27–28.

    Google Scholar

    Chen Guohua, Lan Xiaofeng, Li Fawang, et al. The quantitative analysis way to analyze sulfur dioxide of gas by gas chromatogram[J]. Inner Mongulia Petrochemical Industry, 2009, 35(1): 27–28.

    Google Scholar

    [9] 梁波, 李文修, 崔红淼.新型光纤传感器的特点和应用[J].日用电器, 2015(11): 17–19. doi: 10.3969/j.issn.1673-6079.2015.11.007

    CrossRef Google Scholar

    Liang Bo, Li Wenxiu, Cui Hongmiao. Characteristics and application of new type fiber optic sensor[J]. Electrical Appliances, 2015(11): 17–19. doi: 10.3969/j.issn.1673-6079.2015.11.007

    CrossRef Google Scholar

    [10] 褚状状, 游利兵, 王庆胜, 等.有害气体检测的光纤传感技术发展[J].传感器与微系统, 2016, 35(9): 1–4, 8.

    Google Scholar

    Chu Zhuangzhuang, You Libing, Wang Qingsheng, et al. Development of optical fiber sensing technology for harmful gases detecting[J]. Transducer and Microsystem Technologies, 2016, 35(9): 1–4, 8.

    Google Scholar

    [11] 卜凡云. 基于M-Z干涉仪的光纤气体传感器[D]. 无锡: 江南大学, 2012.

    Google Scholar

    Bu Fanyun. Fiber-optic gas sensor based on M-Z interferometer[D]. Wuxi: Jiangnan University, 2012.http://cdmd.cnki.com.cn/Article/CDMD-10295-1012329476.htm

    Google Scholar

    [12] 郭长立. 一种煤矿瓦斯浓度的光学测量方法: CN102305775A[P]. 2012-01-04.

    Google Scholar

    Guo Changli. Optical measurement method for gas concentration of coal mines: CN102305775A[P]. 2012-01-04.http://www.wanfangdata.com.cn/details/detail.do?_type=patent&id=CN201110253382.5

    Google Scholar

    [13] 张仙玲, 范旭东, 肖韶荣, 等. 一种气体浓度测量方法及测量装置: CN103411888A[P]. 2013-11-27.

    Google Scholar

    Zhang Xianling, Fan Xudong, Xiao Shaorong, et al. Gas concentration measuring method and measuring device: CN103411888A[P]. 2013-11-27.http://d.wanfangdata.com.cn/Patent_CN201310379392.2.aspx

    Google Scholar

    [14] 陈乐君, 刘玉玲, 余飞鸿.光声光谱气体探测器的新发展[J].光学仪器, 2006, 28(5): 86–91.

    Google Scholar

    Chen Lejun, Liu Yuling, Yu Feihong. New research progress of photoacoustic spectroscopy gas detector[J]. Optical Instruments, 2006, 28(5): 86–91.

    Google Scholar

    [15] 张望. 光声光谱微量气体检测技术及其应用研究[D]. 大连: 大连理工大学, 2010.

    Google Scholar

    Zhang Wang. Research on the photoacoustic spectroscopy for trace gas detection and applications[D]. Dalian: Dalian University of Technology, 2010.http://cdmd.cnki.com.cn/Article/CDMD-10141-2011014123.htm

    Google Scholar

    [16] 吕权息, 龙梅丹, 刘龙为.基于光声光谱技术的氟化氢气体检测仪的研究[J].环境科学与技术, 2016, 39(4): 83–87.

    Google Scholar

    Lv Quanxi, Long Meidan, Liu Longwei. Research on gas detector for hydrogen fluoride based on photoacoustic spectroscopy[J]. Environmental Science & Technology, 2016, 39(4): 83–87.

    Google Scholar

    [17] 姜萌, 冯巧玲, 魏宇峰, 等.小型化光声光谱气体传感器研究进展[J].激光与光电子学进展, 2015, 52(2): 020006.

    Google Scholar

    Jiang Meng, Feng Qiaoling, Wei Yufeng, et al. Recent advance in miniaturization of photo-acoustic spectroscopy gas sensor[J]. Laser & Optoelectronics Progress, 2015, 52(2): 020006.

    Google Scholar

    [18] 梁丽荣. 呼出氨气光声光谱检测及医学应用研究[D]. 大连: 大连理工大学, 2012.

    Google Scholar

    Liang Lirong. Breath ammonia measurement based on photoacoustic spectroscopy for medical application[D]. Dalian: Dalian University of Technology, 2012.http://cdmd.cnki.com.cn/Article/CDMD-10141-1012395075.htm

    Google Scholar

    [19] 陈伟根, 周恒逸, 黄会贤, 等.基于半导体激光器的乙炔气体光声光谱检测及其定量分析[J].仪器仪表学报, 2010, 31(3): 665–670.

    Google Scholar

    Chen Weigen, Zhou Hengyi, Huang Huixian, et al. Diode laser based photoacoustic spectroscopy detection of acetylene gas and its quantitative analysis[J]. Chinese Journal of Scientific Instrument, 2010, 31(3): 665–670.

    Google Scholar

    [20] 杨晓龙. 光声光谱技术中的多气体成份分析方法研究[D]. 大连: 大连理工大学, 2003.http://cdmd.cnki.com.cn/Article/CDMD-10141-2003061464.htm

    Google Scholar

    [21] 付松年, 苏立国, 吴重庆, 等.相关光谱法在光纤气体传感中的应用[J].光谱学与光谱分析, 2002, 22(6): 912–915.

    Google Scholar

    Fu Songnian, Su Liguo, Wu Chongqing, et al. Application of correlation spectroscopy method to fiber gas sensor[J]. Spectroscopy and Spectral Analysis, 2002, 22(6): 912–915.

    Google Scholar

    [22] 董小鹏.采用Tm光纤光源的甲烷气体相关光谱检测[J].中国激光, 1994, 21(10):789–794. doi: 10.3321/j.issn:0258-7025.1994.10.005

    CrossRef Google Scholar

    Dong Xiaopeng. Detection of methane gas with fibre correlation spectroscopy, using semiconductor laser diode pumped Tin-doped fibre source[J].Chinese Journal of Lasers, 1994, 21(10): 789–794. doi: 10.3321/j.issn:0258-7025.1994.10.005

    CrossRef Google Scholar

    [23] Dakin J P, Edwards H O, Weigl B H. Progress with optical gas sensors using correlation spectroscopy[J]. Sensors and Actuators B: Chemical, 1995, 29(1–3): 87–93. doi: 10.1016/0925-4005(95)01667-8

    CrossRef Google Scholar

    [24] 乔记平, 秦建敏, 闫晓燕, 等.基于宽带光源与相关光谱技术的CH4传感器研究[J].光电子·激光, 2014, 25(2): 217–221.

    Google Scholar

    Qiao Jiping, Qin Jianmin, Yan Xiaoyan, et al. Study of CH4 sensor based on a broadband light source and correlation spectroscopy[J]. Journal of Optoelectronics·Laser, 2014, 25(2): 217–221.

    Google Scholar

    [25] 张亚男, 赵勇, 王琦, 等.基于相关光谱和差分检测的气体传感系统[J].东北大学学报(自然科学版), 2015, 36(4): 461–464.

    Google Scholar

    Zhang Ya'nan, Zhao Yong, Wang Qi, et al. Gas sensing system based on correlation spectroscopy and differential technology[J]. Journal of Northeastern University (Natural Science Edition), 2015, 36(4): 461–464.

    Google Scholar

    [26] 潘卫东. 基于TDLAS的痕量乙烯气体检测技术研究[D]. 哈尔滨: 哈尔滨工业大学, 2013.

    Google Scholar

    Pan Weidong. Research on tunable diode laser absorption spectroscopy for gas analysis of trace ethylene[D]. Harbin: Harbin Institute of Technology, 2013.http://cdmd.cnki.com.cn/Article/CDMD-10213-1014080649.htm

    Google Scholar

    [27] 姚华. 采用可调谐激光吸收光谱技术遥测甲烷气体浓度的研究[D]. 杭州: 浙江大学, 2011.

    Google Scholar

    Yao Hua. Research on remote sensing of methane based on tunable diode laser absorption spectroscopy technique[D]. Hangzhou: Zhejiang University, 2011.http://cdmd.cnki.com.cn/article/cdmd-10335-1011052287.htm

    Google Scholar

    [28] 阚瑞峰, 刘文清, 张玉钧, 等.基于可调谐激光吸收光谱的大气甲烷监测仪[J].光学学报, 2006, 26(1): 67–70.

    Google Scholar

    Kan Ruifeng, Liu Wenqing, Zhang Yujun, et al. Infrared absorption spectrometer of monitoring ambient methane[J]. Acta Optica Sinica, 2006, 26(1): 67–70.

    Google Scholar

    [29] 许振宇, 刘文清, 阚瑞峰, 等.可调谐半导体激光吸收光谱中的吸光度反演算法研究[J].光谱学与光谱分析, 2010, 30(8): 2201–2204.

    Google Scholar

    Xu Zhenyu, Liu Wenqing, Kan Ruifeng, et al. Study on the arithmetic of absorbance inversion based on tunable diode-laser absorption spectroscopy[J]. Spectroscopy and Spectral Analysis, 2010, 30(8): 2201–2204.

    Google Scholar

    [30] Rothman L S, Gordon I E, Babikov Y, et al. The HITRAN2012 molecular spectroscopic database[J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 2013, 130: 4–50. doi: 10.1016/j.jqsrt.2013.07.002

    CrossRef Google Scholar

    [31] Zhang Shuai, Liu Wenqing, Zhang Yujun, et al. Gas leakage monitoring with scanned-wavelength direct absorption spectroscopy[J]. Chinese Optics Letters, 2010, 8(5): 443–446. doi: 10.3788/COL

    CrossRef Google Scholar

    [32] 徐振峰, 张悦, 李晓, 等.基于波长调制技术的甲烷气体浓度检测的研究[J].仪表技术与传感器, 2007(4): 61–63.

    Google Scholar

    Xu Zhenfeng, Zhang Yue, Li Xiao, et al. Research on methane gas measurement based on wavelength modulation technology[J]. Instrument Technique and Sensor, 2007(4): 61–63.

    Google Scholar

    [33] 伍昂, 吴尚谦, 蔡彦, 等.剩余振幅调制对波长调制光谱信号线型的影响[J].激光技术, 2012, 36(3): 357–360, 378.

    Google Scholar

    Wu Ang, Wu Shangqian, Cai Yan, et al. Effect of RAM on WMS signal line shape[J]. Laser Technology, 2012, 36(3): 357–360, 378.

    Google Scholar

    [34] Huang Jianqiang, Zheng Chuantao, Gao Zongli, et al. Near-infrared methane detection device using wavelength-modulated distributed feedback diode laser around 1.654 µm[J]. Spectroscopy Letters, 2014, 47(3): 197–205. doi: 10.1080/00387010.2013.790062

    CrossRef Google Scholar

    [35] Li Bin, Zheng Chuantao, Liu Huifang, et al. Development and measurement of a near-infrared CH4 detection system using 1.654 μm wavelength-modulated diode laser and open reflective gas sensing probe[J]. Sensors and Actuators B: Chemical, 2016, 225: 188–198. doi: 10.1016/j.snb.2015.11.037

    CrossRef Google Scholar

    [36] 王聪. 光学式污染气体检测技术的研究[D]. 秦皇岛: 燕山大学, 2006.

    Google Scholar

    Wang Cong. Research on optical pollution gas detection technology[D]. Qinhuangdao: Yanshan University, 2006.http://cdmd.cnki.com.cn/Article/CDMD-10216-2007091006.htm

    Google Scholar

    [37] 邓燕.浅谈倏逝波[J].科技资讯, 2010(13): 100, 103. doi: 10.3969/j.issn.1672-3791.2010.13.086

    CrossRef Google Scholar

    [38] Usha S P, Mishra S K, Gupta B D. Fiber optic hydrogen sulfide gas sensors utilizing ZnO thin film/ZnO nanoparticles: a comparison of surface plasmon resonance and lossy mode resonance[J]. Sensors and Actuators B: Chemical, 2015, 218: 196–204. doi: 10.1016/j.snb.2015.04.108

    CrossRef Google Scholar

    [39] Renganathan B, Sastikumar D, Gobi G, et al. Gas sensing properties of a clad modified fiber optic sensor with Ce, Li and Al doped nanocrystalline zinc oxides[J]. Sensors and Actuators B: Chemical, 2011, 156(1): 263–270. doi: 10.1016/j.snb.2011.04.031

    CrossRef Google Scholar

    [40] Shemshad J, Aminossadati S M, Kizil M S. A review of developments in near infrared methane detection based on tunable diode laser[J]. Sensors and Actuators B:Chemical, 2012, 171–172: 77–92.

    Google Scholar

    [41] Devendiran S, Sastikumar D. Gas sensing based on detection of light radiation from a region of modified cladding (nanocrystalline ZnO) of an optical fiber[J]. Optics & Laser Technology, 2017, 89: 186–191.

    Google Scholar

    [42] Wang Wei, Hou Lantian. Present situation and future development in photonic crystal fibers[J]. Laser & Optoelectronics Progress, 2008, 45(2): 43–58.

    Google Scholar

    [43] 景磊. 新型光子晶体光纤气体传感器研究[D]. 天津: 天津大学, 2012.

    Google Scholar

    Jing Lei. Research on novel gas sensors with photonic crystal fibers[D]. Tianjin: Tianjin University, 2012.http://cdmd.cnki.com.cn/Article/CDMD-10056-1013004886.htm

    Google Scholar

    [44] 韦民红, 童敏明, 童夏敏.基于光子晶体光纤传感器的瓦斯监测系统[J].传感器与微系统, 2012, 31(10): 97–99. doi: 10.3969/j.issn.1000-9787.2012.10.029

    CrossRef Google Scholar

    Wei Minhong, Tong Minming, Tong Xiamin. Gas monitoring system based on photonic crystal fiber sensor[J]. Transducer and Microsystem Technologies, 2012, 31(10): 97–99. doi: 10.3969/j.issn.1000-9787.2012.10.029

    CrossRef Google Scholar

    [45] 戴婳. 空芯光子晶体光纤传感器在瓦斯检测系统中的应用[D]. 淮南: 安徽理工大学, 2014.

    Google Scholar

    Dai Hua. Application of application in gas detection system in gas detection system[D]. Huainan: Anhui University of Science and Technology, 2014.http://cdmd.cnki.com.cn/article/cdmd-10361-1014384717.htm

    Google Scholar

    [46] 黄小亮. 基于光子晶体光纤和红外吸收光谱的气体传感系统的研究[D]. 长春: 吉林大学, 2016.

    Google Scholar

    Huang Xiaoliang. Research of gas sensor system based on photonic crystal fiber and infrared absorption spectroscopy[D]. Changchun: Jilin University, 2016.http://cdmd.cnki.com.cn/Article/CDMD-10183-1016083947.htm

    Google Scholar

    [47] Carvalho J P, Lehmann H, Bartelt H, et al. Remote system for detection of low-levels of methane based on photonic crystal fibres and wavelength modulation spectroscopy[J]. Journal of Sensors, 2009, 2009(2):10.

    Google Scholar

    [48] 阴亚芳, 周圆, 杨祎, 等.基于光子晶体光纤的气体传感系统设计与实现[J].半导体光电, 2015, 36(5): 811–814.

    Google Scholar

    Yin Yafang, Zhou Yuan, Yang Yi, et al. Design and implementation of gas sensing system based on photonic crystal fiber[J]. Semiconductor Optoelectronics, 2015, 36(5): 811–814.

    Google Scholar

    [49] 孙顺根. 基于光纤衰荡腔的甲烷气体传感系统研究[D]. 武汉: 华中科技大学, 2011.

    Google Scholar

    Sun Shungen. Study of methane gas detection system based on optical fiber cavity ring-down[D]. Wuhan: Huazhong University of Science & Technology, 2011.http://cdmd.cnki.com.cn/article/cdmd-10487-1012013266.htm

    Google Scholar

    [50] 白璐. 基于光纤环形腔衰荡光谱技术的气体浓度测量方法与实验研究[D]. 沈阳: 东北大学, 2013.

    Google Scholar

    Bai Lu. Research on optical fiber loop cavity ring-down spectroscopy gas concentration measuring method and experiment[D]. Shenyang: Northeastern University, 2013.http://cdmd.cnki.com.cn/Article/CDMD-10145-1015702458.htm

    Google Scholar

    [51] 郭继坤, 赵肖东, 马鹏飞.基于光纤环衰荡腔的甲烷传感系统[J].黑龙江科技大学学报, 2014, 24(4): 405–409.

    Google Scholar

    Guo Jikun, Zhao Xiaodong, Ma Pengfei. Study on methane sensing system based on fiber ring cavity ring-down[J]. Journal of Heilongjiang University of Science and Technology, 2014, 24(4): 405–409.

    Google Scholar

    [52] 崔光磊.基于光纤环衰荡技术的多参量在线监测系统研究[J].武汉理工大学学报, 2011, 33(6): 144–147.

    Google Scholar

    Cui Guanglei. Study of multi-parameter online monitoring system based on fiber-loop ring-down technology[J]. Journal of Wuhan University of Technology, 2011, 33(6): 144–147.

    Google Scholar

    [53] Qian Xiaolong, Zhao Yong, Zhang Ya'nan, et al. Theoretical research of gas sensing method based on photonic crystal cavity and fiber loop ring-down technique[J].Sensors and Actuators B: Chemical, 2016, 228: 665–672. doi: 10.1016/j.snb.2016.01.087

    CrossRef Google Scholar

    [54] Hodgkinson J, Tatam R P. Optical gas sensing: a review[J]. Measurement Science & Technology, 2012, 24(1): 012004.

    Google Scholar

    [55] Mishra S K, Bhardwaj S, Gupta B D. Surface plasmon resonance-based fiber optic sensor for the detection of low concentrations of ammonia gas[J]. IEEE Sensors Journal, 2015, 15(2): 1235–1239. doi: 10.1109/JSEN.2014.2356251

    CrossRef Google Scholar

    [56] Tabassum R, Mishra S K, Gupta B D. Fiber optic hydrogen sulfide gas sensor utilizing surface plasmon resonance of Cu/ZnO thin films [J]. Proceedings of SPIE, 2013, 8794: 87941E.

    Google Scholar

  • With the problem of air pollution and the improvement of life quality, people are increasingly anxious about the surrounding air quality in recent years, which also promotes the development of gas concentration detection technologies. At present, these technologies have focused on electrochemical method, catalytic combustion, gas chromatography and optical methods. Among them, the optical method of gas concentration detection has its unique advantages, such as high sensitivity and high accuracy. Through the combination of optical fiber sensing technology, this method can realize the detection of gas concentration in extreme environment, with the advantages of anti-electromagnetic interference, flame retardant, intrinsically safe, and so on. In contrast, the non-optical detection methods make some bad performance, such as poor sensitivity, bad accuracy and low reproducibility, which are unable to be applied to the industrial site.

    And seven common optical methods for gas concentration detection are described, which contains 3 conventional gas concentration detection technologies and 4 novel methods. The former is composed of optical interferential method, photoacoustic detection (PAS), and correlation spectroscopy. The latter consists of tunable diode laser absorption spectroscopy(TDLAS), evanescent wave field sensing technology, hollow core photonic bandgap fiber(HC-PBF) sensing technology and fiber loop ring-down spectroscopy(FLRDS). The basic principles, advantages and disadvantages of each method are given and compared in detail. The improvement work and some novel ideas are presented. The applications of combined methods are also discussed. The prospect of optical gas sensing is listed, which mainly refers to miniaturization, intelligence, portability, low power consumption, high accuracy, fast response and distributed multi-component telemetry technology.

    At last, some new ideas and technologies have been pointed out for gas concentration sensing, such as seeking sensitive films that can interact with the measured gas, adopting special fibers, or using the cladding doped rare earth elements. In addition, on the basis of evanescent field sensing, researchers combine physics with optics to form surface plasmon resonance fiber gas sensing. And the use of hollow core photonic bandgap fiber for the gas chamber, sharing the way with the optical path, increases the utilization of optical power and can achieve distributed sensing, but the gas diffusion cycle time should be considered. The emergence of laser technology makes the optical detection method more excellent, and with the development of wireless communication technology and the awareness of people's health, harmful gas detection devices will be more and more popular with the family. Simultaneously, the telemetry distributed sensing technology for gas concentration will also become increasingly common in factories.

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