Pulsed quantum cascade laser instrument with compact design for rapid, high sensitivity measurements of trace gases in air
Pulsed quantum cascade laser instrument with compact design for rapid, high sensitivity measurements of trace gases in air
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DOI：
10.1007/s00340-008-3129-9
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发表时间：
2008-09-01
影响因子：
2.1
通讯作者：
Mcgovern, R. M.
中科院分区：
文献类型：
--
作者：
McManus, J. B.;Shorter, J. H.;Mcgovern, R. M.
我们已经开发了一种紧凑的仪器，用于灵敏，快速和连续测量空气中的痕量气体，与甲烷（CH 4），一氧化氮（NO），一氧化二氮（N2 O）和氨（NH 3）的结果在这里。该仪器利用了量子级联（QC）激光器和红外探测器的最新技术，该技术允许在没有低温液体的情况下实现高灵敏度，0.2 ppb（0.2 x 10（-9））的NH3。可以用在不同波长下工作的QC激光器来代替测量其他气体。该仪器连续运行，几乎不需要操作员的注意，并提供基于Web的远程访问，用于仪器控制，校准和数据检索。仪器设计包括热电（TE）冷却的脉冲分布反馈（DFB）QC激光器，一个小容量（0.51）的多程细胞提供76米的吸收路径长度和TE冷却的检测器。用于激光控制和数据分析的集成软件使用直接吸收提供定量痕量气体测量，而无需校准气体。该仪器可用于环境气体的现场测量。
We have developed a compact instrument for sensitive, rapid and continuous measurement of trace gases in air, with results presented here for methane (CH4), nitric oxide (NO), nitrous oxide (N2O) and ammonia (NH3). This instrument takes advantage of recent technology in quantum cascade (QC) lasers and infrared detectors, which allows high sensitivity without cryogenic liquids, e.g., 0.2 ppb (0.2 x 10(-9)) of NH3 in air in 1 s. One may substitute a QC laser operating at a different wavelength to measure other gases. The instrument operates continuously, requiring little operator attention, and web-based remote access is provided for instrument control, calibration and data retrieval. The instrument design includes a thermoelectrically (TE) cooled pulsed distributed feedback (DFB) QC laser, a low volume (0.51) multipass cell offering 76 m absorption path length and a TE cooled detector. Integrated software for laser control and data analysis using direct absorption provides quantitative trace gas measurements without calibration gases. The instrument may be applied to field measurements of gases of environmental concern.