{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T04:49:50Z","timestamp":1785905390237,"version":"3.56.0"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,26]],"date-time":"2021-01-26T00:00:00Z","timestamp":1611619200000},"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>Air pollution in urban areas is a huge concern that demands an efficient air quality control to ensure health quality standards. The hotspots can be located by increasing spatial distribution of ambient air quality monitoring for which the low-cost sensors can be used. However, it is well-known that many factors influence their results. For low-cost Particulate Matter (PM) sensors, high relative humidity can have a significant impact on data quality. In order to eliminate or reduce the impact of high relative humidity on the results obtained from low-cost PM sensors, a low-cost dryer was developed and its effectiveness was investigated. For this purpose, a test chamber was designed, and low-cost PM sensors as well as professional reference devices were installed. A vaporizer regulated the humid conditions in the test chamber. The low-cost dryer heated the sample air with a manually adjustable intensity depending on the voltage. Different voltages were tested to find the optimum one with least energy consumption and maximum drying efficiency. The low-cost PM sensors with and without the low-cost dryer were compared. The experimental results verified that using the low-cost dryer reduced the influence of relative humidity on the low-cost PM sensor results.<\/jats:p>","DOI":"10.3390\/s21030804","type":"journal-article","created":{"date-parts":[[2021,1,26]],"date-time":"2021-01-26T08:29:16Z","timestamp":1611649756000},"page":"804","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Investigating a Low-Cost Dryer Designed for Low-Cost PM Sensors Measuring Ambient Air Quality"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9862-9354","authenticated-orcid":false,"given":"Abdul","family":"Samad","sequence":"first","affiliation":[{"name":"Department of Flue Gas Cleaning and Air Quality Control, Institute of Combustion and Power Plant Technology (IFK), University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Freddy Ernesto","family":"Melchor Mimiaga","sequence":"additional","affiliation":[{"name":"Department of Flue Gas Cleaning and Air Quality Control, Institute of Combustion and Power Plant Technology (IFK), University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernd","family":"Laquai","sequence":"additional","affiliation":[{"name":"Department of Flue Gas Cleaning and Air Quality Control, Institute of Combustion and Power Plant Technology (IFK), University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulrich","family":"Vogt","sequence":"additional","affiliation":[{"name":"Department of Flue Gas Cleaning and Air Quality Control, Institute of Combustion and Power Plant Technology (IFK), University of Stuttgart, Pfaffenwaldring 23, 70569 Stuttgart, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,26]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2020, November 06). Geneva. (2018): 9 out of 10 People Worldwide Breathe Polluted Air, but More Countries Are Taking Action. 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_2","doi-asserted-by":"crossref","unstructured":"Liu, H.-Y., Dunea, D., Iordache, S., and Pohoata, A. (2018). A Review of Airborne Particulate Matter Effects on Young Children\u2019s Respiratory Symptoms and Diseases. Atmosphere, 9.","DOI":"10.3390\/atmos9040150"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.envint.2015.11.007","article-title":"Particulate Matter Air Pollution Components and Risk for Lung Cancer","volume":"87","author":"Beelen","year":"2016","journal-title":"Environ. Int."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1016\/S1470-2045(13)70279-1","article-title":"Air Pollution and Lung Cancer Incidence in 17 European Cohorts: Prospective Analyses from the European Study of Cohorts for Air Pollution Effects (ESCAPE)","volume":"14","author":"Andersen","year":"2013","journal-title":"Lancet Oncol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1016\/j.envint.2015.08.006","article-title":"Association between Long-Term Exposure to Air Pollution and Mortality in France: A 25-Year Follow-Up Study","volume":"85","author":"Bentayeb","year":"2015","journal-title":"Environ. Int."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"8217","DOI":"10.5194\/acp-15-8217-2015","article-title":"Particulate Matter, Air Quality and Climate: Lessons Learned and Future Needs","volume":"15","author":"Fuzzi","year":"2015","journal-title":"Atmos. Chem. Phys. Discuss."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/S0160-4120(02)00181-2","article-title":"Ecological Effects of Particulate Matter","volume":"29","author":"Grantz","year":"2003","journal-title":"Environ. Int."},{"key":"ref_8","unstructured":"European Union (2020, November 15). Sampling Points for Air Quality\u2014Representativeness and Comparability of Measurement in Accordance with Directive 2008\/50\/EC on Ambient Air Quality and Cleaner Air for Europe. Available online: https:\/\/www.europarl.europa.eu\/RegData\/etudes\/STUD\/2019\/631055\/IPOL_STU(2019)631055_EN.pdf."},{"key":"ref_9","unstructured":"Karagulian, F., Gerboles, M., Barbiere, M., Kotsev, A., Lagler, F., and Borowiak, A. (2019). Review of Sensors for Air Quality Monitoring, Publications Office of the European Uion. EUR 29826 EN."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Brattich, E., Bracci, A., Zappi, A., Morozzi, P., Di Sabatino, S., Porc\u00f9, F., Di Nicola, F., and Tositti, L. (2020). How to Get the Best from Low-Cost Particulate Matter Sensors: Guidelines and Practical Recommendations. Sensors, 20.","DOI":"10.3390\/s20113073"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"De Vito, S., Esposito, E., Formisano, F., Massera, E., Fiore, S., Fattoruso, G., Salvato, M., Buonanno, A., Veneri, P.D., and Di Francia, G. (2018). Enabling Citizen Science with A Crowdfunded and Field Validated Smart Air Quality Monitor. Proceedings, 2.","DOI":"10.3390\/proceedings2130932"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e00070","DOI":"10.1016\/j.ohx.2019.e00070","article-title":"Smart Citizen Kit and Station: An Open Environmental Monitoring System for Citizen Participation and Scientific Experimentation","volume":"6","author":"Camprodon","year":"2019","journal-title":"HardwareX"},{"key":"ref_13","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_14","unstructured":"European Commission (2020, January 09). Measuring Air Pollution with Low-Cost Sensors. Available online: https:\/\/ec.europa.eu\/jrc\/en\/publication\/brochures-leaflets\/measuring-air-pollution-low-cost-sensors."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Kouimtzis, T., and Samara, C. (1995). Airborne Particulate Matter, Springer.","DOI":"10.1007\/978-3-540-49145-3"},{"key":"ref_16","unstructured":"Wiseman, C.L.S., and Zereini, F. (2010). Urban Airborne Particulate Matter: Origin, Chemistry, Fate and Health Impacts, Springer."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Rai, P.K. (2015). Biomagnetic Monitoring of Particulate Matter: In the Indo-Burma Hotspot Region, Elsevier.","DOI":"10.1016\/B978-0-12-805135-1.00005-6"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.5194\/amt-7-1121-2014","article-title":"Field Calibrations of a Low-Cost Aerosol Sensor at a Regulatory Monitoring Site in California","volume":"7","author":"Holstius","year":"2014","journal-title":"Atmos. Meas. Tech."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4883","DOI":"10.5194\/amt-11-4883-2018","article-title":"The Influence of Humidity on the Performance of a Low-Cost Air Particle Mass Sensor and the Effect of Atmospheric Fog","volume":"11","author":"Jayaratne","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2018\/5096540","article-title":"Evaluation of Low-Cost Sensors for Ambient PM2.5 Monitoring","volume":"2018","author":"Badura","year":"2018","journal-title":"J. Sensors"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10661-020-8118-4","article-title":"Field Performance of a Low-Cost Sensor in the Monitoring of Particulate Matter in Santiago, Chile","volume":"192","author":"Tagle","year":"2020","journal-title":"Environ. Monit. Assess."},{"key":"ref_22","unstructured":"Akpootu, D., and Gana, N. (2019, May 07). The Effect of Relative Humidity on the Hygroscopic Growth Factor and Bulk Hygroscopicity of Water Soluble Aerosols. Available online: http:\/\/theijes.com\/papers\/v2-i11\/Part.1\/I021101048057.pdf."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Liu, H.Y., Schneider, P., Haugen, R., and Vogt, M. (2019). Performance Assessment of a Low-Cost PM2.5 Sensor for a Near Four-Month Period in Oslo, Norway. Atmosphere, 10.","DOI":"10.3390\/atmos10020041"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7497","DOI":"10.1038\/s41598-019-43716-3","article-title":"Long-Term Field Comparison of Multiple low-Cost Particulate Matter Sensors in an Outdoor Urban Environment","volume":"9","author":"Bulot","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"102076","DOI":"10.1016\/j.scs.2020.102076","article-title":"Evaluation of Low-Cost Sensors for Quantitative Personal Exposure Monitoring","volume":"57","author":"Mahajan","year":"2020","journal-title":"Sustain. Cities Soc."},{"key":"ref_26","unstructured":"Surgaylo, A. (2017). Research on Comparative Measurements of Different Particulate Matter and Soot Measuring Devices and Sensors, University of Stuttgart. Research Project."},{"key":"ref_27","unstructured":"Samad, A., Vogt, U., and Laquai, B. (2018). Outdoor Air Quality Measurements Using Low Cost Particulate Matter Sensors. Proceedings of the III International Conference on Atmospheric Dust\u2014DUST 2018, Bari, Italy, 29\u201331 May 2018, Digilabs Pub."},{"key":"ref_28","unstructured":"Alphasense Ltd. (2018). Alphasense User Manual OPC-N3 Optical Particle Counter, Alphasense Ltd."},{"key":"ref_29","unstructured":"Grimm Aerosol Technik GmbH & Co. KG (2020, January 09). EDM 180 EDM 180 Environmental Dust Monitor for Approved PM Measurements. Available online: https:\/\/www.grimm-aerosol.com\/fileadmin\/files\/grimm-aerosol\/3%20Products\/Environmental%20Dust%20Monitoring\/Approved%20PM%20Monitor\/EDM180_The_Proven\/Product%20PDFs\/Datasheet_EDM180_ENG_2020.pdf."},{"key":"ref_30","unstructured":"KSL Staubtechnik GmbH (2019, May 07). Eskal Dusts. Available online: https:\/\/www.ksl-staubtechnik.de\/en\/glasindustrie\/eskal."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/804\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:15:21Z","timestamp":1760159721000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/804"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,26]]},"references-count":30,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["s21030804"],"URL":"https:\/\/doi.org\/10.3390\/s21030804","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,26]]}}}