{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,5]],"date-time":"2026-09-05T05:27:55Z","timestamp":1788586075321,"version":"build-2803163510"},"reference-count":35,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2010,10,18]],"date-time":"2010-10-18T00:00:00Z","timestamp":1287360000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The increase in greenhouse gas emissions is a serious environmental problem and has stimulated the scientific community to pay attention to the need for detection and monitoring of gases released into the atmosphere. In this regard, the development of sensitive and selective gas sensors has been the subject of several research programs. An important greenhouse gas is sulphur hexafluoride, an almost non-reactive gas widely employed in industrial processes worldwide. Indeed it is estimated that it has a radiative forcing of 0.52 W\/m2. This work compares two photoacoustic spectrometers, one coupled to a CO2 laser and another one coupled to a Quantum Cascade (QC) laser, for the detection of SF6. The laser photoacoustic spectrometers described in this work have been developed for gas detection at small concentrations. Detection limits of 20 ppbv for CO2 laser and 50 ppbv for quantum cascade laser were obtained.<\/jats:p>","DOI":"10.3390\/s101009359","type":"journal-article","created":{"date-parts":[[2010,10,18]],"date-time":"2010-10-18T12:19:09Z","timestamp":1287404349000},"page":"9359-9368","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["A Sulfur Hexafluoride Sensor Using Quantum Cascade and CO2 Laser-Based Photoacoustic Spectroscopy"],"prefix":"10.3390","volume":"10","author":[{"given":"Mila","family":"Rocha","sequence":"first","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcelo","family":"Sthel","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guilherme","family":"Lima","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcelo da","family":"Silva","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Delson","family":"Schramm","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andr\u00e1s","family":"Mikl\u00f3s","sequence":"additional","affiliation":[{"name":"Fraunhofer Institute for Building Physics, Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helion","family":"Vargas","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Ci\u00eancias F\u00edsicas LCFIS, Universidade estadual do Norte Fluminense UENF, Av. Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2010,10,18]]},"reference":[{"key":"ref_1","unstructured":"IPCC (2007). Report of Working Group I. Climate Change 2007, The Physical Science Basis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"217","DOI":"10.2174\/1874282300802010217","article-title":"Target Atmosphere CO2: Where Should Humanity Aim","volume":"2","author":"Hansen","year":"2008","journal-title":"Open Atmos. Sci. J"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"750","DOI":"10.1038\/ngeo338","article-title":"Attribution of Polar Warming to Human Influence","volume":"1","author":"Gillett","year":"2008","journal-title":"Nat. Geosci"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"13905","DOI":"10.1073\/pnas.0602861103","article-title":"Forced and Ungforced Ocean Temperature Changes in Atlantic and Pacific Tropical Cyclogenesis Regions","volume":"103","author":"Sander","year":"2006","journal-title":"PNAS"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1038\/nature03906","article-title":"Increasing Destructiveness of Tropical Cyclones over the Past 30 Years","volume":"436","author":"Emanuel","year":"2005","journal-title":"Nature"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1038\/nature06777","article-title":"Mountain Pine Beetle and Forest Carbon Feedback to Climate Change","volume":"452","author":"Kurz","year":"2008","journal-title":"Nature"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1126\/science.1173951","article-title":"Some Like It Cold, Northern Shrimp Stocks Thrive When Climatic Conditions Lead to Cold Bottom Waters","volume":"324","author":"Greene","year":"2009","journal-title":"Science"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1158","DOI":"10.1038\/nature08017","article-title":"Greenhouse Gas Emission Targets for Limiting Global Warming to 2 \u00b0C","volume":"458","author":"Meinshausen","year":"2009","journal-title":"Nature"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1163","DOI":"10.1038\/nature08019","article-title":"Warning Caused by Cumulative Carbon Emissions towards the Trillionth Tonne","volume":"458","author":"Allen","year":"2009","journal-title":"Nature"},{"key":"ref_10","unstructured":"World Meteorological Organization Available online: http:\/\/www.wmo.int\/pages\/index_en.html (accessed on November 2009)."},{"key":"ref_11","unstructured":"(2010). Inventory of US Greenhouse Gas Emissions and Sinks: 1990\/2008, U.S. Environmental Protection Agency."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s00340-007-2875-4","article-title":"Trace Gas Monitoring with Infrared Laser-Based Detection Schemes","volume":"90","author":"Sigrist","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_13","unstructured":"Rocha, MV, Sthel, M, Silva, MG, Schramm, DU, and Vargas, H (, January June). Greenhouse Gases Detection with Quantum Cascade Laser Photoacustic Spectroscopy. Calgary, Canada. in press."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1007\/s00340-008-3127-y","article-title":"Laser-Based Systems for Trace Gas Detection in Life Sciences","volume":"92","author":"Cristescu","year":"2008","journal-title":"Appl. Phys. B"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1007\/PL00021151","article-title":"Mobile Laser Spectrometer with Novel Resonant Multipass Photoacoustic Cell for Trace-Gas Sensing","volume":"70","author":"Nagele","year":"2000","journal-title":"Appl. Phys. B"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1937","DOI":"10.1063\/1.1353198","article-title":"Application of Acoustic Resonators in Photoacoustic Trace Gas Analysis and Metrology","volume":"4","author":"Miklos","year":"2001","journal-title":"Rev. Sci. Inst"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1051\/jp4:2005125204","article-title":"Photoacoustic Spectroscopy-Based Analysis of Gas Samples in A Bus Station","volume":"125","author":"Sthel","year":"2005","journal-title":"J. Phys. IV France"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1007\/s00340-006-2357-0","article-title":"Photoacoustic Detection of NO2 and N2O Using Quantum Cascade Lasers","volume":"85","author":"Lima","year":"2006","journal-title":"Appl. Phys. B"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1007\/s00340-005-2004-1","article-title":"Photoacustic Measurement of N2O Concentration in Ambient Air with a Pulsed Optical Parametric Oscillator","volume":"82","author":"Miklos","year":"2006","journal-title":"Appl. Phys"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1016\/S1350-4495(03)00125-7","article-title":"Application of Laser Photoacoustic Spectroscopy for The Analysis of Gas Samples Emitted by Diesel Engines","volume":"44","author":"Schramm","year":"2003","journal-title":"Inf. Phys. Technol"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/S0039-9140(03)00418-1","article-title":"Photoacustic Spectrometry for Trace Gas Analysis and Leak Detection Using Different Cell Geometries","volume":"62","author":"Gondal","year":"2004","journal-title":"Talanta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1109\/TDEI.2002.1007706","article-title":"Laser Sensor for Detection of SF6 Leaks in High Insulated Switch Gear Systems","volume":"9","author":"Gondal","year":"2002","journal-title":"IEEE Trans. Dieletrics Eletrical Insulations"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"7083","DOI":"10.1364\/AO.46.007083","article-title":"High Sensitive Electronically Modulated Photoacoustic Spectrometer for Ozone Detection","volume":"46","author":"Gondal","year":"2008","journal-title":"Appl. Opt"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1007\/s00340-002-0963-z","article-title":"Chemical Sensing with Pulsed QC-DFB Lasers Operating at 15.6 \u03bcm","volume":"75","author":"Kosterev","year":"2002","journal-title":"Appl. Phys. B"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3158","DOI":"10.1063\/1.1555271","article-title":"Fast Gas Spectroscopy Using Pulsed Quantum Cascade Lasers","volume":"93","author":"Meyer","year":"2003","journal-title":"J. Appl. Phys"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1513","DOI":"10.1007\/s00340-004-1513-7","article-title":"Photoacoustic Detection of Ozone Using Quantum Cascade Laser","volume":"78","author":"Silva","year":"2004","journal-title":"Appl. Phys. B"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cplett.2009.12.073","article-title":"Quantum Cascade Lasers in Chemical Physics","volume":"487","author":"Curl","year":"2010","journal-title":"Chem. Phys. Lett"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4966","DOI":"10.1364\/AO.45.004966","article-title":"Ammonia Detection Using Quantum-Cascade Laser Photoacoustic Spectroscopy","volume":"45","author":"Baptista","year":"2006","journal-title":"Appl. Opt"},{"key":"ref_29","first-page":"194","article-title":"Photoacoustic Spectroscopy for Trace Gas Detection with Cryogenic for Trace Gas Detection with Cryogenic and Room-Temperature Continuous-Wave Quantum Cascade Lasers","volume":"8","author":"Zeninary","year":"2010","journal-title":"Cent. Eur. J. Phys"},{"key":"ref_30","unstructured":"Killinger, DA, and Mooradian, A (1988). Optics and Laser Remote Sensing Springer Series in Optical Science, Springer-Verlag."},{"key":"ref_31","unstructured":"Measures, RM (1988). Laser Remote Chemical Analysis, John Wiley & Sons."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1016\/1350-4495(94)00046-N","article-title":"New Developments in CO2-Laser Photoacoustic Monitoring of Trace Gases","volume":"36","author":"Thony","year":"1995","journal-title":"Infrared Phys. Technol"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2914","DOI":"10.1063\/1.1147072","article-title":"Geometrical Optimization of a Longitudinal Resonant Photoacoustic Cell for Sensitive and Fast Trace Gas Detection","volume":"67","author":"Bijnen","year":"1996","journal-title":"J. Rev. Sci. Inst"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.postharvbio.2009.07.010","article-title":"Gas Diffusion in \u2018Golden\u2019 Papaya Fruit at Different Maturity Stages","volume":"54","author":"Pereira","year":"2009","journal-title":"Postharvest Biol. Thechnol"},{"key":"ref_35","unstructured":"Available online: http:\/\/www.esrl.noaa.gov\/gmd\/hats\/insitu\/cats\/conc\/mlosf6."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/10\/9359\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:03:36Z","timestamp":1760220216000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/10\/9359"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,10,18]]},"references-count":35,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2010,10]]}},"alternative-id":["s101009359"],"URL":"https:\/\/doi.org\/10.3390\/s101009359","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010,10,18]]}}}