{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T07:00:01Z","timestamp":1775026801339,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2019,2,12]],"date-time":"2019-02-12T00:00:00Z","timestamp":1549929600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Precise, location-specific fine dust measurement is central for the assessment of urban air quality. Classic measurement approaches require dedicated hardware, of which professional equipment is still prohibitively expensive (&gt;10k$) for dense measurements, and inexpensive sensors do not meet accuracy demands. As a step towards filling this gap, we propose FeinPhone, a phone-based fine dust measurement system that uses camera and flashlight functions that are readily available on today\u2019s off-the-shelf smart phones. We introduce a cost-effective passive hardware add-on together with a novel counting approach based on light-scattering particle sensors. Since our approach features a 2D sensor (the camera) instead of a single photodiode, we can employ it to capture the scatter traces from individual particles rather than just retaining a light intensity sum signal as in simple photometers. This is a more direct way of assessing the particle count, it is robust against side effects, e.g., from camera image compression, and enables gaining information on the size spectrum of the particles. Our proof-of-concept evaluation comparing several FeinPhone sensors with data from a high-quality APS\/SMPS (Aerodynamic Particle Sizer\/Scanning Mobility Particle Sizer) reference device at the World Calibration Center for Aerosol Physics shows that the collected data shows excellent correlation with the inhalable coarse fraction of fine dust particles (r &gt; 0.9) and can successfully capture its levels under realistic conditions.<\/jats:p>","DOI":"10.3390\/s19030749","type":"journal-article","created":{"date-parts":[[2019,2,13]],"date-time":"2019-02-13T02:49:44Z","timestamp":1550026184000},"page":"749","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["FeinPhone: Low-cost Smartphone Camera-based 2D Particulate Matter Sensor"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1352-1281","authenticated-orcid":false,"given":"Matthias","family":"Budde","sequence":"first","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6029-4368","authenticated-orcid":false,"given":"Simon","family":"Leiner","sequence":"additional","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0305-3768","authenticated-orcid":false,"given":"Marcel","family":"K\u00f6pke","sequence":"additional","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Johannes","family":"Riesterer","sequence":"additional","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Till","family":"Riedel","sequence":"additional","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Beigl","sequence":"additional","affiliation":[{"name":"Karlsruhe Institute of Technology (KIT), TECO\/Pervasive Computing Systems, Karlsruhe 76131, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,12]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (WHO) (2003). Health Aspects of Air Pollution With Particulate Matter, Ozone And Nitrogen Dioxide, World Health Organization (WHO). Report on a Who Working Group."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"12936","DOI":"10.1073\/pnas.1300018110","article-title":"Evidence on the impact of sustained exposure to air pollution on life expectancy from China\u2019s Huai River policy","volume":"110","author":"Chen","year":"2013","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/j.envres.2016.05.037","article-title":"Association of novel metrics of particulate matter with vascular markers of inflammation and coagulation in susceptible populations\u2013results from a panel study","volume":"150","author":"Schneider","year":"2016","journal-title":"Environ. Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"11369","DOI":"10.1021\/es4022602","article-title":"The Changing Paradigm of Air Pollution Monitoring","volume":"47","author":"Snyder","year":"2013","journal-title":"Environ. Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Mukherjee, A., Stanton, L.G., Graham, A.R., and Roberts, P.T. (2017). Assessing the utility of low-cost particulate matter sensors over a 12-week period in the Cuyama Valley of California. Sensors, 17.","DOI":"10.3390\/s17081805"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Broday, D.M. (2017). Citi-Sense Project Collaborators. Wireless Distributed Environmental Sensor Networks for Air Pollution Measurement\u2014The Promise and the Current Reality. Sensors, 17.","DOI":"10.3390\/s17102263"},{"key":"ref_7","unstructured":"Nova Fitness Co. Ltd. (2017, November 15). SDS011 sensor. Available online: https:\/\/nettigo.pl\/attachments\/398."},{"key":"ref_8","unstructured":"LUBW (2018, January 24). Messungen mit dem Feinstaubsensor SDS011 - Ein Vergleich mit einem eignungsgepr\u00fcften Feinstaubanalysator. Available online: http:\/\/www4.lubw.baden-wuerttemberg.de\/servlet\/is\/268831\/."},{"key":"ref_9","unstructured":"Budde, M., Schwarz, A.D., M\u00fcller, T., Laquai, B., Streibl, N., Schindler, G., K\u00f6pke, M., Riedel, T., Dittler, A., and Beigl, M. (2018). Potential and Limitations of the Low-Cost SDS011 Particle Sensor for Monitoring Urban Air Quality. ProScience, 5."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Budde, M., El Masri, R., Riedel, T., and Beigl, M. (2013, January 2\u20135). Enabling Low-Cost Particulate Matter Measurement for Participatory Sensing Scenarios. Proceedings of the 12th International Conference on Mobile and Ubiquitous Multimedia (MUM 2013), Lule\u00e5, Sweden.","DOI":"10.1145\/2541831.2541859"},{"key":"ref_11","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_12","unstructured":"Retsch Technology (2017, November 18). CAMSIZER X2 Product Information. Available online: https:\/\/www.retsch-technology.de\/de\/api\/?action=product_pdf&productId=399&id=2296509&L=6&print_info=1&print_image=1&print_examples=1&print_advantages=1&print_features=1&print_principle=1."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"9813","DOI":"10.3390\/s140609813","article-title":"A new dusts sensor for cultural heritage applications based on image processing","volume":"14","author":"Proietti","year":"2014","journal-title":"Sensors"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.measurement.2015.01.019","article-title":"Dust detection and analysis in museum environment based on pattern recognition","volume":"66","author":"Proietti","year":"2015","journal-title":"Measurement"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4481","DOI":"10.1016\/j.atmosenv.2011.05.030","article-title":"A cellphone based system for large-scale monitoring of black carbon","volume":"45","author":"Ramanathan","year":"2011","journal-title":"Atmos. Environ."},{"key":"ref_16","unstructured":"Poduri, S., Nimkar, A., and Sukhatme, G.S. (2018, January 24). Visibility Monitoring using Mobile Phones. Available online: http:\/\/citeseerx.ist.psu.edu\/viewdoc\/summary?doi=10.1.1.173.4647."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7351","DOI":"10.1002\/2014GL061462","article-title":"Mapping atmospheric aerosols with a citizen science network of smartphone spectropolarimeters","volume":"41","author":"Snik","year":"2014","journal-title":"Geophys. Res. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.sna.2014.09.003","article-title":"Capacitive detection of micrometric airborne particulate matter for solid-state personal air quality monitors","volume":"219","author":"Carminati","year":"2014","journal-title":"Sens. Actuators A"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Doering, F.L., Paprotny, I., and White, R.M. (2012, January 3\u20137). MEMS air-microfluidic sensor for portable monitoring of airborne particulates. Proceedings of the 2012 Solid-State Sensors, Actuators and Microsystems Workshop, San Diego, CA, USA.","DOI":"10.31438\/trf.hh2012.84"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Budde, M., Barbera, P., El Masri, R., Riedel, T., and Beigl, M. (2013, January 8\u201312). Retrofitting Smartphones to be Used as Particulate Matter Dosimeters. Proceedings of the 17th International Symposium on Wearable Computers (ISWC\u201913), Zurich, Switzerland.","DOI":"10.1145\/2493988.2494342"},{"key":"ref_21","first-page":"13","article-title":"Design of a Light-scattering Particle Sensor for Citizen Science Air Quality Monitoring with Smartphones: Tradeoffs and Experiences","volume":"3","author":"Budde","year":"2016","journal-title":"ProScience"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1109\/TBME.2011.2163157","article-title":"Physiological Parameter Monitoring from Optical Recordings With a Mobile Phone","volume":"59","author":"Scully","year":"2012","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Pelegris, P., Banitsas, K., Orbach, T., and Marias, K. (September, January 31). A Novel Method to Detect Heart Beat Rate Using a Mobile Phone. Proceedings of the 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology, Buenos Aires, Argentina.","DOI":"10.1109\/IEMBS.2010.5626580"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Lamonaca, F., Carn\u00ed, D.L., Grimaldi, D., Nastro, A., Riccio, M., and Spagnolo, V. (2015, January 7\u20139). Blood oxygen saturation measurement by smartphone camera. Proceedings of the 2015 IEEE International Symposium on Medical Measurements and Applications (MeMeA), Turin, Italy.","DOI":"10.1109\/MeMeA.2015.7145228"},{"key":"ref_25","unstructured":"Bui, N., Nguyen, A., Nguyen, P., Truong, H., Ashok, A., Dinh, T., Deterding, R., and Vu, T. (2017, January 6\u20138). PhO2: Smartphone Based Blood Oxygen Level Measurement Systems Using Near-IR and RED Wave-guided Light. Proceedings of the 15th ACM Conference on Embedded Network Sensor Systems, New York, NY, USA."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1904","DOI":"10.1039\/c3ay40116b","article-title":"A novel camera phone-based platform for quantitative fluorescence sensing","volume":"5","author":"MacCraith","year":"2013","journal-title":"Anal. Methods"},{"key":"ref_27","unstructured":"Klein, R.D. (2017, November 21). RadioAcivity\u2014RadioactivityCounter for Mobile Phones. Available online: http:\/\/www.hotray-info.de\/html\/radioactivity.html."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1109\/MCOM.2010.5560598","article-title":"A survey of mobile phone sensing","volume":"48","author":"Lane","year":"2010","journal-title":"IEEE Commun. Mag."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Budde, M., K\u00f6pke, M., and Beigl, M. (2015, January 7\u201311). Robust In-situ Data Reconstruction from Poisson Noise for Low-cost, Mobile, Non-expert Environmental Sensing. Proceedings of the 19th International Symposium on Wearable Computers (ISWC\u201915), Osaka, Japan.","DOI":"10.1145\/2802083.2808406"},{"key":"ref_30","unstructured":"Bradski, G. (2019, January 07). The OpenCV Library. Available online: http:\/\/www.drdobbs.com\/open-source\/the-opencv-library\/184404319."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Zivkovic, Z. (2004, January 26). Improved adaptive Gaussian mixture model for background subtraction. Proceedings of the 17th International Conference on Pattern Recognition (ICPR 2004), Cambridge, UK.","DOI":"10.1109\/ICPR.2004.1333992"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1016\/j.patrec.2005.11.005","article-title":"Efficient adaptive density estimation per image pixel for the task of background subtraction","volume":"27","author":"Zivkovic","year":"2006","journal-title":"Pattern Recognit. Lett."},{"key":"ref_33","unstructured":"TSI (2017, November 13). Aerodynamic Particle Sizer Model 3321. Available online: http:\/\/www.tsi.com\/uploadedFiles\/_Site_Root\/Products\/Literature\/Spec_Sheets\/3321.pdf."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"657","DOI":"10.5194\/amt-5-657-2012","article-title":"Mobility particle size spectrometers: Harmonization of technical standards and data structure to facilitate high quality long-term observations of atmospheric particle number size distributions","volume":"5","author":"Wiedensohler","year":"2012","journal-title":"Atmos. Meas. Tech."},{"key":"ref_35","unstructured":"Budde, M. (2018). Distributed, Low-Cost, Non-Expert Fine Dust Sensing with Smartphones. [Ph.D. Thesis, Karlsruhe Institute of Technology (KIT)]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/3\/749\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:31:32Z","timestamp":1760185892000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/3\/749"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,2,12]]},"references-count":35,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2019,2]]}},"alternative-id":["s19030749"],"URL":"https:\/\/doi.org\/10.3390\/s19030749","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,2,12]]}}}