Abstract
A portable remote methane detector based on infrared-absorption spectroscopy using an InGaAsP distributed-feedback laser is described. This equipment transmits a laser beam and detects a fraction of the backscatter reflected from the target. From this, the detector thereby measures the integrated methane concentration between the detector and the target. The equipment operator can easily detect methane clouds at a distance by hand-scanning the laser beam. To achieve a high sensitivity of detection, wavelength-modulation spectroscopy is applied to the infrared-absorption measurement for methane. The wavelength of the light source is modulated at a frequency of 10 kHz, and the center wavelength is stabilized at the center of the 2ν3 band R(3) line of methane (1.65372 μm). When used with typical targets at distances up to 10 m, the detector has a detection limit of less than 5 ppm-m. To the best of the author’s knowledge, the detector is the only hand-held product capable of remote methane detection. Recently, this novel equipment was commercially introduced into the Japanese market as a product named the Portable Remote Methane Detector (PRMD). Some PRMD units were in research use for detecting methane emissions from garbage landfills, although the PRMD was mainly developed for remote detection of leaks from natural gas pipelines. The author expects that the PRMD could become the standard equipment for field measurements of methane emissions from land.
Similar content being viewed by others
References
Iseki T, Miyaji M (2003) A portable remote methane detector using a tunable diode laser. 22nd World Gas Conference Tokyo, TF 5-C 09 op
Iseki T, Tai H, Kimura K (2000) A portable remote methane sensor using a tunable diode laser. Measure Sci Technol 11:594–602
Reid J, Labrie D (1981) Second-harmonic detection with tunable diode lasers: comparison of experiment and theory. Appl Phys B 26:203–210
Rothman LS, Rinsland CP, Goldman A, Massie ST, Edwards DP, Flaud JM, Perrin AA, Camy-Peyret A and others (1998) The HITRAN molecular spectroscopic database and Hawks (HITRAN atmospheric workstation. J Quant Spectrosc Radiat Transfer 60(2):665–710
Uehara K, Tai H (1992) Remote detection of methane with a 1.66-μm diode laser. Appl Optics 31:809–814
Uehara K, Tai H, Kimura K (1997) Real-time monitoring of environmental methane and other gases with semiconductor lasers: a review. Sens Act B 38–39:136–140
Verma SB, Ullman FG, Billesbach D, Clement RJ, Kim J, Verry ES (1992) Eddy correlation measurements of methane flux in a northernpeatland ecosystem. Bound-Layer Meteorol 58(3):289–304
Watson RT, Core Writing Team (eds) (2001) Climate change 2001: synthesis report. A contribution of working groups I, II and III to the third assessment report of the intergovernmental panel on climate change. Cambridge University Press, New York
Acknowledgements
The author expresses thanks to his research group members in Tokyo Gas Co. Ltd., Anritsu Corporation, and Tokyo Gas Engineering Co. Ltd. for their cooperation during the development of the PRMD. The author also wish to thank Dr. Tanikawa, associate professor of the Hokkaido University, Dr. Yamada, Senior researcher of the National Institute for Environmental Studies, and Dr. Ishigaki, researcher of the National Institute for Environmental Studies, for their valuable advise.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Iseki, T. A portable remote methane detector using an InGaAsP DFB laser. Env Geol 46, 1064–1069 (2004). https://doi.org/10.1007/s00254-004-1094-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00254-004-1094-0