Applications of a tunable diode laser absorption spectrometer in monitoring greenhouse gases

作者：Wang Min^*; Zhang Yujun; Liu Jianguo; Liu Wenqing; Kan Ruifeng; Wang Tiedong; Chen Dong; Chen Jiuying; Wang Xiaomei; Xia Hui; Fang Xi

来源：Chinese Optics Letters, 2006, 4(6): 363-365.

• Multiple reflection cell
• Near infrared tunable diode laser
• Second harmonic detection
• Time response
• Tunable diode laser absorption spectroscopy (TDLAS)

Tunable diode laser absorption spectroscopy (TDLAS) is a powerful technique to measure trace gas, which can provide high sensitivity, high selectivity, and fast time response. A brief description of our instruments with room-temperature near infrared tunable diode laser designed to measure greenhouse gas (i.e., CH4, CO2) in the ambient air is presented. A multiple-reflection cell and the second harmonic detection technique are used to lower the detection limit. The detection limit of the instrument is below 100 ppbv for CH4 and 10 ppmv for CO2, which is enough to the measurements of ambient CH4 and CO2. The instruments have been used to monitor the methane and carbon dioxide of the ambient air in a long time in Fengtai, Beijing. The results of measurement are shown and discussed in this paper.

• 出版日期2006