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Atmos. Meas. Tech. Discuss., 5, 2567-2590, 2012
www.atmos-meas-tech-discuss.net/5/2567/2012/ doi:10.5194/amtd-5-2567-2012 © Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License. |
Performance of a low-cost methane sensor for ambient concentration measurements in preliminary studies
1ETH Zurich, Institute of Agricultural Sciences, Universitätsstrasse 2, 8092 Zurich, Switzerland
2University of Michigan, Department of Ecology & Evolutionary Biology, Ann Arbor, MI 48109-1048, USA
Abstract. Methane is the second most important greenhouse gas after CO2 and contributes to global warming. Its sources are not uniformly distributed across terrestrial and aquatic ecosystems, and most of the methane flux is expected to stem from hotspots which often occupy a very small fraction of the total landscape area. Continuous time-series measurements of CH4 concentrations can help identify and locate these methane hot-spots. Newer, low-cost trace gas sensors such as the Figaro TGS 2600 can detect CH4 even at ambient concentrations. Hence, in this paper we tested this sensor under real-world conditions over Toolik Lake, Alaska, to determine its suitability for preliminary studies before placing more expensive and service-intensive equipment at a given locality. A reasonably good agreement with parallel measurements made using a Los Gatos Research FMA 100 methane analyzer was found after removal of the strong cross-sensitivities for temperature and relative humidity. Correcting for this cross-sensitivity increased the absolute accuracy required for in-depth studies, and the reproducibility between two TGS 2600 sensors run in parallel is very good. We conclude that the relative CH4 concentrations derived from such sensors are sufficient for preliminary investigations in the search of potential methane hot-spots.
Citation: Eugster, W. and Kling, G. W.: Performance of a low-cost methane sensor for ambient concentration measurements in preliminary studies, Atmos. Meas. Tech. Discuss., 5, 2567-2590, doi:10.5194/amtd-5-2567-2012, 2012.