摘要
由于工业监控和环境检测的需要,基于红外吸收光谱分析原理,研制甲烷传感系统,日益得到人们的关注。文章描绘了甲烷中红外的基频吸收带和近红外的2ν+23ν组合带、23ν泛频带的吸收光谱强度分布,并给出了相应的吸收光谱曲线。定量数据表明,甲烷的基频吸收要比泛频吸收高两个数量级以上,较组合频吸收高3个数量级以上。文章还介绍了甲烷检测的差分技术、谐波技术、腔光谱增强技术、以及光声技术,给出了相应检测方法的理论公式、能够达到的检测灵敏度以及系统的结构。这些技术的有效性已经被研究报道所证明。
There has been considerable interest recently in methane sensor based on infrared absorption spectroscopy for industrial detection and environment monitoring.The present paper presents the intensites of methane mid-infrared fundamental absorption bands,near-infrared combination band of ν2＋2ν3 and overtone band of 2ν3,and it was found that the absorption strengths of fundamental bands are two orders of magnitude higher than those of overtone bands and three orders of magnitude higher than those of the combinations.Theoretically,mid-infrared detection system is much better.However,because the near-infrared source and detector are more maturely developed and cheaper,near-infrared technology is widely used.Furthermore,the near-infrared radiation can be transmitted through ordinary low-loss silica fiber, suitable for long-distance methane sensing system,meeting the needs of industrial mining and other aspects.But with the development of mid-infrared detector and high-power high-sensitivity devices,low priced micro sensor modules will be more and more developed.The development of optical methane sensors is reported in this paper.Several detection technologies were investigated such as differential absorption,harmonic detection,cavity spectroscopy enhancement and photoacoustic spectroscopy.The theoretical formula,sensitivity and system structure of these technologies are presented.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2008年第11期2515-2519,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(60477012)资助
关键词
红外吸收
甲烷
谐波检测
光谱增强
光声效应
Infrared absorption,Methane,Harmonic detection,Spectra enhancement,Photoacoustic effect
