应用光学, 2014, 35 (2): 264, 网络出版: 2014-04-09
NO2分子高灵敏度痕量探测技术研究
High-sensitive trace detection of NO2 with broadband cavity-enhanced spectroscopy
激光光谱 非相干宽带腔增强吸收光谱 NO2分子 高灵敏度痕量探测 laser spectroscopy incoherent broadband cavity-enhanced absorption sp NO2 molecule high-sensitive trace detection
摘要
搭建了一台基于蓝光LED的非相干宽带腔增强吸收光谱系统, 并将其应用于NO2分子的高灵敏度痕量探测研究。在3 s采样时间下, 系统探测灵敏度为3.2×10-9 cm-1(1 σ), 对应NO2的探测极限约为187 pmol/mol。利用Allan方差对系统最佳采样时间及系统稳定性进行分析, 当采样时间延长至30 s时, 系统的探测极限可提高至44 pmol/mol。将该系统应用于实际大气中NO2的连续测量, 其测量结果与商业化NOx分析仪(Thermo 42i)进行了比对测试。
Abstract
A blue light emitting diode (LED) based incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument was set up for high sensitive detection of NO2 molecule. A detection sensitivity of 3.2×10-9 cm-1 (1σ, 300 ms integrating time, and 10 times average) was demonstrated on the basis of absorption spectroscopy of NO2, corresponding to a minimum detection concentration of about 187 pmol/mol for NO2. The measurement sensitivity and optimum acquisition time of the IBBCEAS system were evaluated using Allan variance analysis. The detection limit of 44 pmol/mol for NO2 was achieved with an optimum acquisition time of 30 s. The IBBCEAS measured NO2 data in ambient air were compared to the values measured with an on-line NOx analyzer (Thermo 42i). Result shows a good agreement between the NOx analyzer and the IBBCEAS.
董美丽, 徐学哲, 赵卫雄, 顾学军, 胡长进, 盖艳波, 高晓明, 黄伟, 张为俊. NO2分子高灵敏度痕量探测技术研究[J]. 应用光学, 2014, 35(2): 264. DONG Mei-li, XU Xue-zhe, ZHAO Wei-xiong, GU Xue-jun, HU Chang-jin, GAI Yan-bo, GAO Xiao-ming, HUANG Wei, ZHANG Wei-jun. High-sensitive trace detection of NO2 with broadband cavity-enhanced spectroscopy[J]. Journal of Applied Optics, 2014, 35(2): 264.