{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T04:35:40Z","timestamp":1769920540028,"version":"3.49.0"},"reference-count":33,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2019,2,17]],"date-time":"2019-02-17T00:00:00Z","timestamp":1550361600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2017YFC0209700"],"award-info":[{"award-number":["2017YFC0209700"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2016YFC0303900"],"award-info":[{"award-number":["2016YFC0303900"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61775221"],"award-info":[{"award-number":["61775221"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41730103"],"award-info":[{"award-number":["41730103"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004739","name":"Youth Innovation Promotion Association of the Chinese Academy of Sciences","doi-asserted-by":"publisher","award":["2015263"],"award-info":[{"award-number":["2015263"]}],"id":[{"id":"10.13039\/501100004739","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A sensitive dual-gas sensor for the detection of CH4 and C2H6 is demonstrated. Two tunable semiconductor lasers operating at 1.653 \u03bcm (for CH4 monitoring) and 1.684 \u03bcm (for C2H6) were used as the light source for spectroscopic measurements of CH4 and C2H6. Long-path absorption in a home-made compact dense-pattern multipass cell (Leff = 29.37 m) was employed, combined with wavelength modulation and second harmonic detection. Simultaneous detection of CH4 and C2H6 was achieved by separated wavelength modulations of the two lasers. Modulation frequencies and amplitudes were optimized for sensitivity detection of CH4 and C2H6 simultaneously. The dual-gas sensor exhibits 1\u03c3 detection limits of 1.5 ppbv for CH4 in 140 s averaging time and 100 ppbv for C2H6 in 200 s.<\/jats:p>","DOI":"10.3390\/s19040820","type":"journal-article","created":{"date-parts":[[2019,2,17]],"date-time":"2019-02-17T22:11:50Z","timestamp":1550441510000},"page":"820","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Dual-Gas Sensor of CH4\/C2H6 Based on Wavelength Modulation Spectroscopy Coupled to a Home-Made Compact Dense-Pattern Multipass Cell"],"prefix":"10.3390","volume":"19","author":[{"given":"Xing","family":"Tian","sequence":"first","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"}]},{"given":"Yuan","family":"Cao","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"}]},{"given":"Jiajin","family":"Chen","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5813-5093","authenticated-orcid":false,"given":"Kun","family":"Liu","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9828-5424","authenticated-orcid":false,"given":"Guishi","family":"Wang","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]},{"given":"Tu","family":"Tan","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]},{"given":"Jiaoxu","family":"Mei","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6141-1039","authenticated-orcid":false,"given":"Weidong","family":"Chen","sequence":"additional","affiliation":[{"name":"Laboratoire de Physicochimie de l\u2019Atmosph\u00e8re, Universit\u00e9 du Littoral C\u00f4te d\u2019Opale, 189A, Av. Maurice Schumann, 59140 Dunkerque, France"}]},{"given":"Xiaoming","family":"Gao","sequence":"additional","affiliation":[{"name":"Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Science, Hefei 230031, China"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2109","DOI":"10.1021\/ie071083w","article-title":"Natural Gas Processing with Membranes: An Overview","volume":"47","author":"Baker","year":"2008","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.jngse.2016.06.030","article-title":"Natural gas origin, composition, and processing: A review","volume":"34","author":"Faramawy","year":"2016","journal-title":"J. Nat. Gas Sci. Eng."},{"key":"ref_3","first-page":"D21306","article-title":"Global budget of ethane and regional constraints on U.S. sources","volume":"113","author":"Xiao","year":"2008","journal-title":"J. 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