Journal article
Development of a Portable Aerosol Collector and Spectrometer (PACS)
Aerosol science and technology, Vol.52(12), pp.1351-1369
12/02/2018
DOI: 10.1080/02786826.2018.1524985
PMCID: PMC10468716
PMID: 37654799
Abstract
This article presents the development of a Portable Aerosol Collector and Spectrometer (PACS), an instrument designed to measure particle number, surface area, and mass concentrations continuously and time-weighted mass concentration by composition from 10 nm to 10 µm. The PACS consists of a six-stage particle size selector, a valve system, a water condensation particle counter to detect number concentrations, and a photometer to detect mass concentrations. The stages of the selector include three impactor and two diffusion stages, which resolve particles by size and collect particles for later chemical analysis. Particle penetration by size was measured through each stage to determine actual collection performance and account for particle losses. The data inversion algorithm uses an adaptive grid-search process with a constrained linear least-square solver to fit a tri-modal (ultrafine, fine, and coarse), log-normal distribution to the input data (number and mass concentration exiting each stage). The measured 50% cutoff diameter of each stage was similar to the design. The pressure drop of each stage was sufficiently low to permit its operation with portable air pumps. Sensitivity studies were conducted to explore the influence of unknown particle density (range from 500 to 3,000 kg/m
3
) and shape factor (range from 1.0 to 3.0) on algorithm output. Assuming standard density spheres, the aerosol size distributions fit well with a normalized mean bias of −4.9% to 3.5%, normalized mean error of 3.3% to 27.6%, and R
2
values of 0.90 to 1.00. The fitted number and mass concentration biases were within ±10% regardless of uncertainties in density and shape. However, fitted surface area concentrations were more likely to be underestimated/overestimated due to the variation in particle density and shape. The PACS represents a novel way to simultaneously assess airborne aerosol composition and concentration by number, surface area, and mass over a wide size range.
Copyright © 2018 American Association for Aerosol Research
Details
- Title: Subtitle
- Development of a Portable Aerosol Collector and Spectrometer (PACS)
- Creators
- Changjie Cai - Department of Occupational and Environmental Health, University of Oklahoma Health Sciences Center, University of OklahomaGeb W Thomas - Department of Mechanical and Industrial Engineering, University of IowaTianbao Yang - Department of Computer Science, The University of IowaJae Hong Park - School of Health Sciences, Purdue UniversitySivaram P Gogineni - Spectral Energies, LLCThomas M Peters - Department of Occupational and Environmental Health, University of Iowa
- Resource Type
- Journal article
- Publication Details
- Aerosol science and technology, Vol.52(12), pp.1351-1369
- DOI
- 10.1080/02786826.2018.1524985
- PMID
- 37654799
- PMCID
- PMC10468716
- NLM abbreviation
- Aerosol Sci Technol
- ISSN
- 0278-6826
- eISSN
- 1521-7388
- Publisher
- Taylor & Francis
- Grant note
- U.S. Air Force AF131-024 / small-business innovative research NIEHS/NIH P30 ES005605 / University of Iowa Environmental Health Sciences Research Center NIOSH T42OH008491 / Heartland Center for Occupational Health & Safety
- Language
- English
- Date published
- 12/02/2018
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Occupational and Environmental Health; Orthopedics and Rehabilitation; Industrial and Systems Engineering; Computer Science
- Record Identifier
- 9983997477002771
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