Author(s): Yanhai Wang, Xiaoman Wang, Yong Zhu
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Volume 4 - Oct 2015
In order to detect trace methane (CH4) with non contact, the proposed manuscript describes high sensitivity trace methane detector using quantum cascaded laser (QCL) with centre wavelength at 7.5 μm, which is based on combination of Tunable Diode Laser Absorption Spectroscopy (TDLAS) and Wavelength Modulation Spectroscopy (WMS). Under room temperature, the spectrum of QCL can scan CH4 absorption line via adjusting the injection current of QCL. Meanwhile, a compact herriott cell (40 cm long and 800 ml volume) is utilized to achieve a total optical path with 16 meters length. The aforementioned detector is applied to detect CH4 with different concentrations, results show that the relative detection error is less than 7%, the lowest detection is 1×10-6. Meanwhile, the researchers can detect other gases through replace lasers with different wavelength.
Spectroscopy, TDLAS-WMS, Trace Methane, Quantum Cascaded Laser (QCL), Herriott Cell
- S.L. Bai, L.Y. Chen, P.C. Yang, et al, Sn/In/Ti nanocomposite sensor for CH4 detection [J]. Sensors and Actuators B, 2008, 135(1): 1-6.
- A. Kock, A. Tischner, T. Maier, et al, Atmospheric pressure fabrication of SnO2-nanowires for highly sensitive CO and CH¬4 detection [J]. Sensors and Actuators B, 2009, 138 (1): 160-167.
- K. Namjou, S. Cai, and E. A. Whittaker, et al. Sensitive absorption spectroscopy with a room-temperature distributed-feedback  quantum-cascade laser[J].Optics Letters，1998, 23(3):219-221.
- G. Durry, J.S. Li, I. Vinogradov, et al, Near infrared diode laser spectroscopy of C2H2, H2O, CO2 and their isotopologues and the application to TDLAS, a tunable diode laser spectrometer for the martian PHOBOS-GRUNT space mission [J]. Appl Phys B, 2010, 99(1-2): 339–351.
- Yuan Song, Kan Ruifeng, He Yabai, et al.. Laser temperature compensation used in tunable diode laser absorption spectroscopy[J]. Chinese J Lasers, 2013, 40(5): 0515002.
- Ye W L, Zheng C T, Yu X, et al.. Design and performances of a mid-infrared CH4 detection device with novel three-channel-based LS-FTF self-adaptive denoising structure[J]. Sensors and Actuators B, 2011, 155(1):37-45.
- Tao L, Sun K, Khan M A, et al.. Compact and portable open-path sensor for simultaneous measurements of atmospheric N2O and CO using a quantum cascade laser[J]. Optics Express, 2012, 20(27): 28106-28118.
- Chen Chen, Wang Biao, Li Chunguang, et al.. A trace gas sensor using mid-infrared quantum cascade laser at 4.8μm to detect carbon monoxide[J]. Spectroscopy and Spectral Analysis, 2014,34(3):838-842.
- Chen Chen, Robert W. Newcomb, Yiding Wang. A trace methane gas sensor using mid-infrared quantum cascaded laser at 7.5 μm[J]. Applied Physics B, 2013, 113(4): 491-501.
- Wagner S, Klein M, Kathrotia T, et al.. Absolute, spatially resolved, in situ CO profiles in atmospheric laminar counter flow diffusion flames using 2.3 μm TDLAS[J]. Applied Physics B, 2012, 109(3): 533-540.
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