单光纤环甲烷气体传感器的研究
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摘要
近年来,随着煤矿业、环境监测、石油化工等行业对甲烷气体浓度检测的重视,可靠、实时、快速越来成为甲烷气体检测的追求方向。光纤传感器其抗电磁干扰力强、灵敏度高、重量轻、易集成等特点,倍受国内外学者关注。
本文所设计的光纤传感系统,是基于气体光谱吸收特性的单环光纤系统,气室置于单环中,采用耦合器分光,光脉冲多次经单环形成光功率损耗,并分别对初始状态和气体吸收状态下的光脉冲波形进行了分析拟合处理,通过计算出衰荡时间来确定气体吸收损耗,从而测算出气体浓度。
本文以此思想为指导,对光纤衰荡环作了详细的理论分析,得出测量气体浓度的理论依据,并对系统各部分进行测试,搭建了光纤网络系统。还根据实验需求,设计制作了光信号源的驱动电路板,实现了直流偏置、交流调制、温控、显示功能,给光纤传感器提供了可靠的光脉冲信号。通过这种方法测得的气体浓度,与标准浓度基本吻合。
In recent years, as mining industry, environment monitoring and petrochemical industry being more concerned with methane gas detection, detecting reliably, instantly and rapidly must be the main direction and objection. Optical fiber sensor, due to its electromagnetic immunity, high sensitivity, light weight and easy integration has grasped more attention.
Placing gas cell in single-loop optical fiber, an optical fiber sensing system is designed which based on spectrum absorption principle of methane gas. Light pulse generated by DFBLD split up into two parts by coupler, the optical power of one part of which pass through the single-loop optical fiber several times will be attenuated. By fitting the curve of the optical pulse power in the original state and in the gas absorption state, ring-down time is figured out to gain gas absorption loss and gas concentration.
On the basis of the principle, a detailed analysis of the fiber ring-down theory is made, by which the gas concentration is figured out, the parts of the system are tested, and structural system is built. Taking account to the system need, driver circuit of DFBLD is designed to achieve the direct current driving, alternating current driving and temperature monitoring, so a reliable light pulse signal are attained. The gas concentration gained by this way is basically coincident with the standards.
本文所设计的光纤传感系统,是基于气体光谱吸收特性的单环光纤系统,气室置于单环中,采用耦合器分光,光脉冲多次经单环形成光功率损耗,并分别对初始状态和气体吸收状态下的光脉冲波形进行了分析拟合处理,通过计算出衰荡时间来确定气体吸收损耗,从而测算出气体浓度。
本文以此思想为指导,对光纤衰荡环作了详细的理论分析,得出测量气体浓度的理论依据,并对系统各部分进行测试,搭建了光纤网络系统。还根据实验需求,设计制作了光信号源的驱动电路板,实现了直流偏置、交流调制、温控、显示功能,给光纤传感器提供了可靠的光脉冲信号。通过这种方法测得的气体浓度,与标准浓度基本吻合。
In recent years, as mining industry, environment monitoring and petrochemical industry being more concerned with methane gas detection, detecting reliably, instantly and rapidly must be the main direction and objection. Optical fiber sensor, due to its electromagnetic immunity, high sensitivity, light weight and easy integration has grasped more attention.
Placing gas cell in single-loop optical fiber, an optical fiber sensing system is designed which based on spectrum absorption principle of methane gas. Light pulse generated by DFBLD split up into two parts by coupler, the optical power of one part of which pass through the single-loop optical fiber several times will be attenuated. By fitting the curve of the optical pulse power in the original state and in the gas absorption state, ring-down time is figured out to gain gas absorption loss and gas concentration.
On the basis of the principle, a detailed analysis of the fiber ring-down theory is made, by which the gas concentration is figured out, the parts of the system are tested, and structural system is built. Taking account to the system need, driver circuit of DFBLD is designed to achieve the direct current driving, alternating current driving and temperature monitoring, so a reliable light pulse signal are attained. The gas concentration gained by this way is basically coincident with the standards.
引文
[1]靳伟,廖延彪,张志鹏.导波光学传感器原理与技术.北京：科学出版社,1998.254-255
[2]王汝林.矿井瓦斯传感器的近代研究方法及方向.煤矿自动化.1998.(1)：16-18
[3]刘迎春,叶湘滨.传感器原理设计及应用.国防科技大学出版社.2004：290
[4]刘志存.催化元件变流检测矿井瓦斯.传感器技术.2003.22(11)：24-26
[5]Brain Culshaw, Emery I Moor, Zhang Zhi Peng. Advanced in Optical Fiber Sensors. SPIE Optical Engineering Press.1992
[6]H. Inaba, T. Kobayasi, M. Hirama. Optical-Fiber Network System for Air-pollution Monitoring over a Wide Area by Optical Absorption Method. Electronics Letters.1979 (23).749-751
[7]K. Chan, H. Ito, H. Inaba. 1Okm-Long Fiber-Optic Remote Sensing of CH4Gas by Near Infrared Absorption. Applied Physics B.1985(38).11-15
[8]J. P. Dakin, C. A. Wade, D. Pinehbeek. A Novel Optical Fiber Methane Sensor. Proc. SPIE.1987.(734):187-190
[9]H. Tai, K. Yamamoto, S. Osawa. Remote Detection of Methane Using a 1.66 um Diode Laser in Combination with Optical Fibers. Proceedings 7th OFS.1990:51-54
[10]B. Culshaw, G. Stewart, F. Dong. Fibre Optic Techniques for Remote Spectroscopic Methane Detection-from Concept to System Realisation. Sensors and Actuators B 51. 1998:25-37
[11]刘文琦,牛德芳.光纤甲烷气体传感器的研究.仪表技术与传感器.1999.(1)：35-36
[12]叶险峰,汤伟中.CH4气体光纤传感器的研究.半导体光电.2000.(3)：218-220
[13]王玉田,郭增军,王莉田.差分吸收式光纤甲烷气体传感器的研究.光电子激光.2001.12(7)：675-678
[14]王玉田,李晓听,刘占伟等.甲烷气体多点光纤传感系统的研究.光电工程.2004.31(6)：21-23
[15]李晓心.燕山大学工学硕士学位论文.2005：12-14
[16]李庆波.利用LED进行甲烷检测的实验研究.吉林大学硕士学位论文.2003：28-29
[17]丁的.大气中部分分子的高灵敏吸收光谱.中国科学技术大学博士学位论文.2004：1-21
[18]A. J. Rest, R. Warren, S. C. Murray. Assignment of Overtones and Combination Bands for Liquid Methane Across the Near Infrared Spectrum. Spectiochimica Acta Part A 52(1996): 1455-463
[19]I. Klimant. Recent Investigations in Oxygen Densing. Proceedings 1st European conference on optical chemical sensors and biosensors.1992.(4):12-15
[20]王侠,宋东草,杨尚明等.光纤甲烷气体传感器可行性研究.烟台大学学报.2004.17(2)：101-105
[2]王汝林.矿井瓦斯传感器的近代研究方法及方向.煤矿自动化.1998.(1)：16-18
[3]刘迎春,叶湘滨.传感器原理设计及应用.国防科技大学出版社.2004：290
[4]刘志存.催化元件变流检测矿井瓦斯.传感器技术.2003.22(11)：24-26
[5]Brain Culshaw, Emery I Moor, Zhang Zhi Peng. Advanced in Optical Fiber Sensors. SPIE Optical Engineering Press.1992
[6]H. Inaba, T. Kobayasi, M. Hirama. Optical-Fiber Network System for Air-pollution Monitoring over a Wide Area by Optical Absorption Method. Electronics Letters.1979 (23).749-751
[7]K. Chan, H. Ito, H. Inaba. 1Okm-Long Fiber-Optic Remote Sensing of CH4Gas by Near Infrared Absorption. Applied Physics B.1985(38).11-15
[8]J. P. Dakin, C. A. Wade, D. Pinehbeek. A Novel Optical Fiber Methane Sensor. Proc. SPIE.1987.(734):187-190
[9]H. Tai, K. Yamamoto, S. Osawa. Remote Detection of Methane Using a 1.66 um Diode Laser in Combination with Optical Fibers. Proceedings 7th OFS.1990:51-54
[10]B. Culshaw, G. Stewart, F. Dong. Fibre Optic Techniques for Remote Spectroscopic Methane Detection-from Concept to System Realisation. Sensors and Actuators B 51. 1998:25-37
[11]刘文琦,牛德芳.光纤甲烷气体传感器的研究.仪表技术与传感器.1999.(1)：35-36
[12]叶险峰,汤伟中.CH4气体光纤传感器的研究.半导体光电.2000.(3)：218-220
[13]王玉田,郭增军,王莉田.差分吸收式光纤甲烷气体传感器的研究.光电子激光.2001.12(7)：675-678
[14]王玉田,李晓听,刘占伟等.甲烷气体多点光纤传感系统的研究.光电工程.2004.31(6)：21-23
[15]李晓心.燕山大学工学硕士学位论文.2005：12-14
[16]李庆波.利用LED进行甲烷检测的实验研究.吉林大学硕士学位论文.2003：28-29
[17]丁的.大气中部分分子的高灵敏吸收光谱.中国科学技术大学博士学位论文.2004：1-21
[18]A. J. Rest, R. Warren, S. C. Murray. Assignment of Overtones and Combination Bands for Liquid Methane Across the Near Infrared Spectrum. Spectiochimica Acta Part A 52(1996): 1455-463
[19]I. Klimant. Recent Investigations in Oxygen Densing. Proceedings 1st European conference on optical chemical sensors and biosensors.1992.(4):12-15
[20]王侠,宋东草,杨尚明等.光纤甲烷气体传感器可行性研究.烟台大学学报.2004.17(2)：101-105