Low-Cost Air Quality Sensor Evaluation and Calibration in Contrasting Aerosol Environments

Low-Cost Air Quality Sensor Evaluation and Calibration in Contrasting Aerosol Environments | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Low-Cost Air Quality Sensor Evaluation and Calibration in Contrasting Aerosol Environments Pawan Gupta, Prakash Doraiswamy, Alqamah Sayeed, Palak Balyan, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7601780/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The use of low-cost sensors (LCS) in air quality monitoring has been gaining interest across all walks of society, including community and citizen scientists, academic research groups, environmental agencies, and the private sector. Traditional air monitoring, performed by regulatory agencies, involves expensive regulatory-grade equipment and requires ongoing maintenance and quality control checks. The low-price tag, minimal operating cost, ease of use, and open data access are the primary driving factors behind the popularity of LCS. This study discusses the role and associated challenges of PM 2.5 sensors in monitoring air quality. We present the results of evaluations of the PurpleAir (PA.) PA-II LCS against regulatory-grade PM 2.5 federal equivalent methods (FEM) and the development of sensor calibration algorithms. The LCS calibration was performed for 2 to 4 weeks during December 2019-January 2020 in Raleigh, NC, and Delhi, India, to evaluate the data quality under different aerosols loadings and environmental conditions. This exercise aims to develop a robust calibration model that uses PA measured parameters (i.e., PM 2.5 , temperature, relative humidity) as input and provides bias-corrected PM 2.5 output at an hourly scale. Thus, the calibration model relies on simultaneous measurements of PM 2.5 by FEM as target output during the calibration model development process. We applied various statistical and machine learning methods to achieve a regional calibration model. The results from our study indicate that, with proper calibration, we can achieve bias-corrected PM 2.5 data using PA sensors within 12% percentage mean absolute bias at hourly and within 6% for a daily average. Our study also suggests that pre-deployment calibrations developed at local or regional scales should be performed for the PA sensors to correct data from the field for scientific data analysis. Particulate Matter Purple Air Machine Learning Low-cost Sensors Full Text Additional Declarations No competing interests reported. Supplementary Files Supmatrev2v1.docx Supmat12082025.docx Supmat01072026.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7601780","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":579444724,"identity":"a1b22762-3f46-4d97-af32-40afaddb147d","order_by":0,"name":"Pawan Gupta","email":"","orcid":"","institution":"NASA Goddard Space Flight Center","correspondingAuthor":false,"prefix":"","firstName":"Pawan","middleName":"","lastName":"Gupta","suffix":""},{"id":579444725,"identity":"d1f3b6d1-9240-47e6-a4de-19217e028f86","order_by":1,"name":"Prakash Doraiswamy","email":"","orcid":"","institution":"RTI International","correspondingAuthor":false,"prefix":"","firstName":"Prakash","middleName":"","lastName":"Doraiswamy","suffix":""},{"id":579444726,"identity":"41ad8613-9a38-4893-b3ea-1f4110e55979","order_by":2,"name":"Alqamah Sayeed","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCElEQVRIiWNgGAWjYDACdjB5AMpjsyFCCzOqljTStRwmrIO/mXnjpxs1dxjk288YPvhQdj6Pv//wA8YvFbj1ShxmK5bOOfaMweBMjrHhjHO3iyVupBkwy5zBY91hHgPpHKB7DBhyzKR5224nNtxgMGCWbMPtKfnDPMa/c/4dZpDvf2P++2/bucT5549/wKvF4DCPmXRuG9AZN3LMmBnbDiRuOJBjwPixDXdoGx5mK7PO7QM678azYsmec8mJG2/kFBxmOINbi9zx5s23c74dlpPvT9744UeZXeK888c3PvxRIYHb+0C3gQgeBgYOA6QwwacBqgUI2B/AhRh/4NcyCkbBKBgFIwsAAJxpW08bEKYnAAAAAElFTkSuQmCC","orcid":"","institution":"NASA Marshall Space Flight Center","correspondingAuthor":true,"prefix":"","firstName":"Alqamah","middleName":"","lastName":"Sayeed","suffix":""},{"id":579444727,"identity":"1667ee8b-1852-4a68-97a4-63eee22bad2a","order_by":3,"name":"Palak Balyan","email":"","orcid":"","institution":"Indian Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Palak","middleName":"","lastName":"Balyan","suffix":""},{"id":579444728,"identity":"07289756-a3d4-4a83-aaf3-90224de5da2a","order_by":4,"name":"Sagnik Dey","email":"","orcid":"","institution":"Indian Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Sagnik","middleName":"","lastName":"Dey","suffix":""},{"id":579444729,"identity":"a0310559-6e35-434e-884f-053f7aca6f61","order_by":5,"name":"Ryan Chartier","email":"","orcid":"","institution":"RTI International","correspondingAuthor":false,"prefix":"","firstName":"Ryan","middleName":"","lastName":"Chartier","suffix":""},{"id":579444730,"identity":"cdb1d149-0ac0-4b3b-a62b-d8116cc9c713","order_by":6,"name":"Robert C. 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