{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T21:37:00Z","timestamp":1769722620494,"version":"3.49.0"},"reference-count":31,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,22]],"date-time":"2020-05-22T00:00:00Z","timestamp":1590105600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"H2020 ITN Marie Sk\u0142odowska-Curie","award":["860808"],"award-info":[{"award-number":["860808"]}]},{"name":"THORLABS GmbH","award":["Polysense Lab"],"award-info":[{"award-number":["Polysense Lab"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A dual-gas sensor based on the combination of a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor and an electronic hygrometer was realized for the simultaneous detection of methane (CH4) and water vapor (H2O) in air. The QEPAS sensor employed an interband cascade laser operating at 3.34 \u03bcm capable of targeting a CH4 absorption line at 2988.8 cm\u22121 and a water line at 2988.6 cm\u22121. Water vapor was measured with both the electronic hygrometer and the QEPAS sensor for comparison. The measurement accuracy provided by the hygrometer enabled the adjustment of methane QEPAS signal with respect to the water vapor concentration to retrieve the actual CH4 concentration. The sensor was tested by performing prolonged measurements of CH4 and H2O over 60 h to demonstrate the effectiveness of this approach for environmental monitoring applications.<\/jats:p>","DOI":"10.3390\/s20102935","type":"journal-article","created":{"date-parts":[[2020,5,22]],"date-time":"2020-05-22T10:18:18Z","timestamp":1590142698000},"page":"2935","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["Environmental Monitoring of Methane with Quartz-Enhanced Photoacoustic Spectroscopy Exploiting an Electronic Hygrometer to Compensate the H2O Influence on the Sensor Signal"],"prefix":"10.3390","volume":"20","author":[{"given":"Arianna","family":"Elefante","sequence":"first","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"}]},{"given":"Giansergio","family":"Menduni","sequence":"additional","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"},{"name":"Photonics Research Group, Department of Electrical and Information Engineering, Polytechnic University of Bari, 70126 Bari, Italy"}]},{"given":"Hubert","family":"Rossmadl","sequence":"additional","affiliation":[{"name":"Thorlabs GmbH, M\u00fcnchner Weg 1, 85232 Bergkirchen, Germany"}]},{"given":"Verena","family":"Mackowiak","sequence":"additional","affiliation":[{"name":"Thorlabs GmbH, M\u00fcnchner Weg 1, 85232 Bergkirchen, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2603-7648","authenticated-orcid":false,"given":"Marilena","family":"Giglio","sequence":"additional","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"}]},{"given":"Angelo","family":"Sampaolo","sequence":"additional","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"}]},{"given":"Pietro","family":"Patimisco","sequence":"additional","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0802-4464","authenticated-orcid":false,"given":"Vittorio M. N.","family":"Passaro","sequence":"additional","affiliation":[{"name":"Photonics Research Group, Department of Electrical and Information Engineering, Polytechnic University of Bari, 70126 Bari, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4867-8166","authenticated-orcid":false,"given":"Vincenzo","family":"Spagnolo","sequence":"additional","affiliation":[{"name":"PolySense Lab-Physics Department, University and Polytechnic of Bari, CNR-IFN, 70126 Bari, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,22]]},"reference":[{"key":"ref_1","unstructured":"Earth System Research Laboratory (2020, March 17). Global Monitoring Division, Available online: https:\/\/esrl.noaa.gov\/gmd\/ccgg\/trends_ch4."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"501","DOI":"10.1016\/j.snb.2016.07.092","article-title":"Potential of a low-cost gas sensor for atmospheric methane monitoring","volume":"238","author":"Rose","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1000","DOI":"10.1016\/j.snb.2015.05.136","article-title":"Highly sensitive detection of methane by near-infrared laser absorption spectroscopy using a compact dense-pattern multipass cell","volume":"220","author":"Liu","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1007\/s00340-008-3135-y","article-title":"A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor","volume":"92","author":"Crosson","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1030","DOI":"10.1080\/03067319.2018.1517871","article-title":"Comparison of portable devices for sub-ambient concentration measurements of methane (CH4) and nitrous oxide (N2O) in soil research","volume":"98","author":"Warlo","year":"2018","journal-title":"Int. J. Environ. Anal. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"012004","DOI":"10.1088\/0957-0233\/24\/1\/012004","article-title":"Optical gas sensing: A review","volume":"24","author":"Hodgkinson","year":"2012","journal-title":"Meas. Sci. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1007\/s00340-014-5828-8","article-title":"Single-QCL-based absorption sensor for simultaneous trace-gas detection of CH4 and N2O","volume":"117","author":"Ren","year":"2014","journal-title":"Appl. Phys. B"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.infrared.2018.12.023","article-title":"A hollow-core photonic band-gap fiber based methane sensor system capable of reduced mode interference noise","volume":"97","author":"Hu","year":"2019","journal-title":"Infrared Phys. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1016\/j.snb.2016.12.146","article-title":"Development and field deployment of a mid-infrared methane sensor without pressure control using interband cascade laser absorption spectroscopy","volume":"244","author":"Zheng","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1007\/s00340-012-4908-x","article-title":"Compact QEPAS sensor for trace methane and ammonia detection in impure hydrogen","volume":"107","author":"Dong","year":"2012","journal-title":"Appl. Phys. B"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"952","DOI":"10.1016\/j.snb.2018.11.132","article-title":"Methane, ethane and propane detection using a compact quartz enhanced photoacoustic sensor and a single interband cascade laser","volume":"282","author":"Sampaolo","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"100159","DOI":"10.1016\/j.pacs.2019.100159","article-title":"Broadband detection of methane and nitrous oxide using a distributed-feedback quantum cascade laser array and quartz-enhanced photoacoustic sensing","volume":"17","author":"Giglio","year":"2020","journal-title":"Photoacoustics"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"011106","DOI":"10.1063\/1.5013612","article-title":"Recent advances in quartz enhanced photoacoustic sensing","volume":"5","author":"Patimisco","year":"2018","journal-title":"Appl. Phys. Rev."},{"key":"ref_14","first-page":"169","article-title":"Quartz-enhanced photoacoustic spectrophones exploiting custom tuning forks: A review","volume":"2","author":"Patimisco","year":"2017","journal-title":"Adv. Phys. X"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Yin, X., Dong, L., Zheng, H., Liu, X., Wu, H., Yang, Y., Ma, W., Zhang, L., Yin, W., and Xiao, L. (2016). Impact of humidity on quartz-enhanced photoacoustic spectroscopy based CO detection using a near-IR telecommunication diode laser. Sensors, 16.","DOI":"10.3390\/s16020162"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1007\/s00340-005-2076-y","article-title":"Near-infrared laser photoacoustic detection of methane: The impact of molecular relaxation","volume":"82","author":"Schilt","year":"2006","journal-title":"Appl. Phys. B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1401","DOI":"10.1364\/OE.27.001401","article-title":"Tuning forks with optimized geometries for quartz-enhanced photoacoustic spectroscopy","volume":"27","author":"Patimisco","year":"2019","journal-title":"Opt. Express"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1007\/s00340-008-3056-9","article-title":"QEPAS methane sensor performance for humidified gases","volume":"92","author":"Kosterev","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1007\/s00340-006-2369-9","article-title":"Influence of molecular relaxation dynamics on quartz-enhanced photoacoustic detection of CO2 at \u03bb = 2 \u03bcm","volume":"85","author":"Wysocki","year":"2006","journal-title":"Appl. Phys. B"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1007\/s00340-012-4949-1","article-title":"Ultra-sensitive carbon monoxide detection by using EC-QCL based quartz-enhanced photoacoustic spectroscopy","volume":"107","author":"Dong","year":"2012","journal-title":"Appl. Phys. B"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"82680F","DOI":"10.1117\/12.905621","article-title":"Sensitive detection of nitric oxide using a 5.26 \u03bcm external cavity quantum cascade laser based QEPAS sensor","volume":"8268","author":"Tittel","year":"2012","journal-title":"Quantum Sens. Nanophotonic Devices IX"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"24037","DOI":"10.1364\/OE.19.024037","article-title":"Ppb-level detection of nitric oxide using an external cavity quantum cascade laser based QEPAS sensor","volume":"19","author":"Dong","year":"2011","journal-title":"Opt. Express"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"12866","DOI":"10.1021\/acs.analchem.9b02709","article-title":"Dual-gas quartz-enhanced photoacoustic sensor for simultaneous detection of methane\/nitrous oxide and water vapor","volume":"91","author":"Elefante","year":"2019","journal-title":"Anal. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2121","DOI":"10.1364\/OE.23.002121","article-title":"Simultaneous atmospheric nitrous oxide, methane and water vapor detection with a single continuous wave quantum cascade laser","volume":"23","author":"Cao","year":"2015","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"126753","DOI":"10.1016\/j.snb.2019.126753","article-title":"Atmospheric CH4 measurement near a landfill using an ICL-based QEPAS sensor with VT relaxation self-calibration","volume":"297","author":"Wu","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.jqsrt.2017.06.038","article-title":"The HITRAN2016 molecular spectroscopic database","volume":"203","author":"Gordon","year":"2017","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1109\/TUFFC.2015.2495013","article-title":"Allan Deviation Plot as a Tool for Quartz Enhanced Photoacoustic Sensors Noise Analysis","volume":"63","author":"Giglio","year":"2016","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Control"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1046","DOI":"10.1175\/1520-0493(1980)108<1046:TCOEPT>2.0.CO;2","article-title":"The computation of equivalent potential temperature","volume":"108","author":"Bolton","year":"1980","journal-title":"Mon. Weather Rev."},{"key":"ref_29","unstructured":"Wallace, J.M., and Hobbs, P.V. (2006). Atmospheric Science: An Introductory Survey, Elsevier."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"15331","DOI":"10.1038\/ncomms15331","article-title":"Beat frequency quartz-enhanced photoacoustic spectroscopy for fast and calibration-free continuous trace-gas monitoring","volume":"8","author":"Wu","year":"2017","journal-title":"Nat. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Rousseau, R., Maurin, N., Trzpil, W., Bahriz, M., and Vicet, A. (2019). Quartz Tuning Fork Resonance Tracking and application in Quartz Enhanced Photoacoustics Spectroscopy. 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