{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T18:13:00Z","timestamp":1781115180498,"version":"3.54.1"},"reference-count":36,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2020,9,10]],"date-time":"2020-09-10T00:00:00Z","timestamp":1599696000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["01LP1602H"],"award-info":[{"award-number":["01LP1602H"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Using low-cost gas sensors for air quality monitoring promises cost effective and convenient measurement systems. Nevertheless, the results obtained have a questionable quality due to different factors that can affect sensor performance. The most discussed ones are relative humidity and air temperature. This investigation aimed to assess the behavior of B4-series low-cost gas sensors from Alphasense for measuring CO, NO, NO2, and O3 for different levels of relative humidity and temperature. These low-cost gas sensors were tested for six relative humidity levels from 10% to 85% with increasing steps of 15% and four temperature levels of 10 \u00b0C, 25 \u00b0C, 35 \u00b0C, and 45 \u00b0C against reference instruments in the laboratory. The effect of these parameters on low-cost gas sensors was quantified in laboratory from which a correction algorithm was calculated, which was then applied to the field data. The applied algorithm improved the data quality of the low-cost gas sensors in most of the cases. Additionally, a low-cost dryer was assessed to reduce the influence of these factors on the low-cost gas sensors, which also proved to be suitable to enhance the data quality.<\/jats:p>","DOI":"10.3390\/s20185175","type":"journal-article","created":{"date-parts":[[2020,9,10]],"date-time":"2020-09-10T09:10:09Z","timestamp":1599729009000},"page":"5175","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":72,"title":["Effect of Relative Humidity and Air Temperature on the Results Obtained from Low-Cost Gas Sensors for Ambient Air Quality Measurements"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9862-9354","authenticated-orcid":false,"given":"Abdul","family":"Samad","sequence":"first","affiliation":[{"name":"Institute of Combustion and Power Plant Technology (IFK), Department of Air Quality Control, University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel Ricardo","family":"Obando Nu\u00f1ez","sequence":"additional","affiliation":[{"name":"Institute of Combustion and Power Plant Technology (IFK), Department of Air Quality Control, University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Grecia Carolina","family":"Solis Castillo","sequence":"additional","affiliation":[{"name":"Institute of Combustion and Power Plant Technology (IFK), Department of Air Quality Control, University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernd","family":"Laquai","sequence":"additional","affiliation":[{"name":"Institute of Combustion and Power Plant Technology (IFK), Department of Air Quality Control, University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulrich","family":"Vogt","sequence":"additional","affiliation":[{"name":"Institute of Combustion and Power Plant Technology (IFK), Department of Air Quality Control, University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.envpol.2007.06.012","article-title":"Human health effects of air pollution","volume":"151","author":"Kampa","year":"2008","journal-title":"Environ. Pollut."},{"key":"ref_2","unstructured":"World Health Organization (2018). 9 out of 10 People Worldwide Breathe Polluted Air, but More Countries Are Taking Action, World Health Organization. Available online: https:\/\/www.who.int\/news-room\/detail\/02-05-2018-9-out-of-10-people-worldwide-breathe-polluted-air-but-more-countries-are-taking-action."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1046\/j.1365-2745.1998.8650717.x","article-title":"The effects of air-borne nitrogen pollutants on species diversity in natural and semi-natural European vegetation","volume":"86","author":"Bobbink","year":"1998","journal-title":"J. Ecol."},{"key":"ref_4","unstructured":"Spangl, W., Schneider, J., Moosmann, L., and Nagl, C. (2007). Representativeness and Classification of Air Quality Monitoring Stations, Umweltbundesamt GmbH. Available online: https:\/\/www.umweltbundesamt.at\/fileadmin\/site\/publikationen\/REP0121.pdf."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.envint.2014.11.019","article-title":"The rise of low-cost sensing for managing air pollution in cities","volume":"75","author":"Kumar","year":"2015","journal-title":"Environ. Int."},{"key":"ref_6","unstructured":"DIN EN 14211, 2012: DIN EN 14211 (2019, October 10). Ambient Air\u2014Standard Method for the Measurement of the Concentration of Nitrogen Dioxide and Nitrogen Monoxide by Chemiluminescence. Available online: https:\/\/www.beuth.de\/en\/standard\/din-en-14211\/146720023."},{"key":"ref_7","unstructured":"DIN EN 14625, 2012: DIN EN 14625 (2019, October 10). Ambient Air\u2014Standard Method for the Measurement of the Concentration of Ozone by Ultraviolet Photometry. Available online: https:\/\/www.beuth.de\/en\/standard\/din-en-14625\/146720212."},{"key":"ref_8","unstructured":"DIN EN 14626, 2012: DIN EN 14626 (2019, October 10). Ambient Air\u2014Standard Method for the Measurement of the Concentration of Carbon Monoxide by Non-Dispersive Infrared Spectroscopy. Available online: https:\/\/www.beuth.de\/en\/standard\/din-en-14626\/146720254."},{"key":"ref_9","unstructured":"Gerboles, M., and Spinelle, L. (2012). Low-cost Gas Sensors for Air Quality Monitoring: Overview in Europe and New Trends, European Commission."},{"key":"ref_10","unstructured":"Williams, R., Kilaru, V., Snyder, E., Kaufman, A., Dye, T., Rutter, A., Russell, A., and Hafner, H. (2019, September 07). Air Sensor Guidebook. US Environ. Prot. Agency 2014. Available online: http:\/\/tdenviro.com\/wp-content\/uploads\/2017\/05\/AirSensorGuidebook.pdf."},{"key":"ref_11","unstructured":"Gerboles, M., Spinelle, L., and Borowiak, A. (2017). Brochure Low-Cost Sensors. Thoughts on the Quality of Data Measured by Sensors, European Commission. Available online: https:\/\/publications.jrc.ec.europa.eu\/repository\/bitstream\/JRC107461\/low_cost_sensors_web.pdf."},{"key":"ref_12","unstructured":"Surgaylo, A. (2018). Development of a Measurement Platform by Using Low-Cost Air Quality Sensors for Air Quality Measurements. [Master\u2019s Thesis, University of Stuttgart]."},{"key":"ref_13","unstructured":"Membrapor (2015). Electrochemical Gas Sensors. Application Note MEM1, Membrapor."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Karagulian, F., Barbiere, M., Kotsev, A., Spinelle, L., Gerboles, M., Lagler, F., Redon, N., Crunaire, S., and Borowiak, A. (2019). Review of the Performance of Low-Cost Sensors for Air Quality Monitoring. Atmosphere, 10.","DOI":"10.3390\/atmos10090506"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1016\/j.snb.2018.03.144","article-title":"The impacts of water vapour and co-pollutants on the performance of electrochemical gas sensors used for air quality monitoring","volume":"266","author":"Pang","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_16","unstructured":"Solis, G. (2019). Test and Analysis of Key Factors that Can Affect the Reliability of Results Obtained from Low-Cost Sensors for Outdoor Air Quality Measurements. [Master\u2019s Thesis, University of Stuttgart]."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Bigi, A., Mueller, M., Grange, S.K., Ghermandi, G., and Hueglin, C. (2018). Performance of NO, NO2 low cost sensors and three calibration approaches within a real world application. Atmos. Meas. Tech. Discuss., 1\u201329.","DOI":"10.5194\/amt-2018-26"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Wei, P., Ning, Z., Ye, S., Sun, L., Yang, F., Wong, K.C., Westerdahl, D., and Louie, P.K. (2018). Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring. Sensors, 18.","DOI":"10.3390\/s18020059"},{"key":"ref_19","unstructured":"Jensen, C.K. (2016). Assessing the Applicability of Low-Cost Electrochemical Gas Sensors for Urban Air Quality Monitoring, IT University of Copenhagen, Pervasive Interaction Technology Laboratory."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/j.envint.2016.12.007","article-title":"Can commercial low-cost sensor platforms contribute to air quality monitoring and exposure estimates?","volume":"99","author":"Castell","year":"2017","journal-title":"Environ. Int."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.atmosenv.2012.11.060","article-title":"The use of electrochemical sensors for monitoring urban air quality in low-cost, high-density networks","volume":"70","author":"Mead","year":"2013","journal-title":"Atmos. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1016\/j.snb.2016.09.020","article-title":"Electrochemical ozone sensors: A miniaturised alternative for ozone measurements in laboratory experiments and air-quality monitoring","volume":"240","author":"Pang","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Sun, L., Westerdahl, D., and Ning, Z. (2017). Development and Evaluation of A Novel and Cost-Effective Approach for Low-Cost NO\u2082 Sensor Drift Correction. Sensors, 17.","DOI":"10.3390\/s17081916"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3325","DOI":"10.5194\/amt-7-3325-2014","article-title":"The next generation of low-cost personal air quality sensors for quantitative exposure monitoring","volume":"7","author":"Piedrahita","year":"2014","journal-title":"Atmos. Measurement Tech."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3783","DOI":"10.5194\/amt-10-3783-2017","article-title":"Design of an ozone and nitrogen dioxide sensor unit and its long-term operation within a sensor network in the city of Zurich","volume":"10","author":"Mueller","year":"2017","journal-title":"Atmos. Meas. Tech."},{"key":"ref_26","first-page":"100027","article-title":"Structuring an integrated air quality monitoring network in large urban areas\u2014Discussing the purpose, criteria and deployment strategy","volume":"2","author":"Munir","year":"2019","journal-title":"Atmos. Environ. X"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"315","DOI":"10.5194\/amt-11-315-2018","article-title":"Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments","volume":"11","author":"Hagan","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.atmosenv.2016.09.050","article-title":"Assessment of air quality microsensors versus reference methods: The EuNetAir joint exercise","volume":"147","author":"Borrego","year":"2016","journal-title":"Atmos. Environ."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.snb.2015.03.031","article-title":"Field calibration of a cluster of low-cost available sensors for air quality monitoring. Part A: Ozone and nitrogen dioxide","volume":"215","author":"Spinelle","year":"2015","journal-title":"Sens. Actuators B Chem."},{"key":"ref_30","unstructured":"Boney, B. (2017). Calibration Using Supervised Learning for Low-Cost Air Quality Sensors. [Master\u2019s Thesis, University of Canterbury]."},{"key":"ref_31","unstructured":"Herod, K.K. (2018). Analyzing and Optimizing an Array of Low-Cost Gas Sensors for Use in An Air Quality Measurement Device with Machine Learning. [Master\u2019s Thesis, Department of Chemical Engineering and Applied Chemistry, University of Toronto]."},{"key":"ref_32","unstructured":"Popoola, O.A.M. (2012). Studies of Urban Air Quality Using Electrochemical Based Sensor Instruments, University of Cambridge."},{"key":"ref_33","unstructured":"(2019, August 15). Perma Pure\u2014Nafion TM: Dryers and Humidifiers; Featuring Nafion Technology. Available online: https:\/\/www.permapure.com\/scientific-emissions\/wp-content\/uploads\/2013\/01\/100-Nafion.pdf."},{"key":"ref_34","unstructured":"U.S. Environmental Protection Agency (2019, August 15). Technical Support Document for the Clear Skies Act 2003 Air Quality Modeling Analysis, Available online: https:\/\/archive.epa.gov\/clearskies\/web\/pdf\/aq_modeling_tsd_csa2003.pdf."},{"key":"ref_35","unstructured":"EP6-A (2003). NCCLS 2003. Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach, NCCLS. Approved Guideline."},{"key":"ref_36","unstructured":"(2019, October 10). Regierungspr\u00e4sidium Stuttgart (2018): Luftreinhalteplan f\u00fcr den Regierungsbezirk Stuttgart\u2014Teilplan Landeshauptstadt Stuttgart der PM10- und NO2-Belastungen. 3. Fortschreibung des Luftreinhalteplanes zur Minderung der PM10- und NO2-Belastungen. Stuttgart, Germany. Available online: https:\/\/rp.baden-wuerttemberg.de\/rps\/Abt5\/Ref541\/Luftreinhalteplan\/541_s_luft_stutt_LRP_3_FS_2018.pdf."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/18\/5175\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:08:50Z","timestamp":1760177330000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/18\/5175"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,9,10]]},"references-count":36,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2020,9]]}},"alternative-id":["s20185175"],"URL":"https:\/\/doi.org\/10.3390\/s20185175","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,9,10]]}}}