Sources of Error and Variability in Particulate Matter Sensor Network Measurements

Details

• Personal Author:
  Koehler K ; Peters TM ; Sousan S ; Stebounova LV ; Thomas G ; Zuidema C
• Description:
  The quality of mass concentration estimates from increasingly popular networks of low-cost particulate matter sensors depends on accurate conversion of sensor output (e.g., voltage) into gravimetric-equivalent mass concentration, typically using a calibration procedure. This study evaluates two important sources of variability that lead to error in estimating gravimetric-equivalent mass concentration: the temporal changes in sensor calibration and the spatial and temporal variability in gravimetric correction factors. A 40-node sensor network was deployed in a heavy vehicle manufacturing facility for 8 months. At a central location in the facility, particulate matter was continuously measured with three sensors of the network and a traditional, higher-cost photometer, determining the calibration slope and intercept needed to translate sensor output to photometric-equivalent mass concentration. Throughout the facility, during three intensive sampling campaigns, respirable mass concentrations were measured with gravimetric samplers and photometers to determine correction factors needed to adjust photometric-equivalent to gravimetric-equivalent mass concentration. Both field-determined sensor calibration slopes and intercepts were statistically different than those estimated in the laboratory (a = 0.05), emphasizing the importance of aerosol properties when converting voltage to photometric-equivalent mass concentration and the need for field calibration to determine slope. Evidence suggested the sensors' weekly field calibration slope decreased and intercept increased, indicating the sensors were deteriorating over time. The mean correction factor in the cutting and shot blasting area (2.9) was substantially and statistically lower than that in the machining and welding area (4.6; p = 0.01). Therefore, different correction factors should be determined near different occupational processes to accurately estimate particle mass concentrations. [Description provided by NIOSH]
• Subjects:
  Aerosols Occupational Health Particulate Matter Safety
• Keywords:
  Aerosol Particles Aerosol Sampling Author Keywords: Correction Factor Field Calibration Low-cost Sensors Particle Composition Particulate Matter Concentration Particulates Photometer Photometry Sampling Sensors

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Iowa ; Maryland ; North Carolina ; OSHA Region 10 ; OSHA Region 3 ; OSHA Region 4 ; OSHA Region 7 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  16
• Issue:
  8
• NIOSHTIC Number:
  nn:20058233
• Citation:
  J Occup Environ Hyg 2019 Aug; 16(8):564-574
• Contact Point Address:
  Thomas M. Peters, Department of Occupational and Environmental Health, 105 River St, S331 CPHB, University of Iowa, Iowa City, IA 52242-5000
• Email:
  thomas-m-peters@uiowa.edu
• Federal Fiscal Year:
  2019
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  True
• Start Date:
  20140901
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20180831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b3f81d9cd64a017d725351002a4ca25513668aecee4f2f222e3db0e09581302b9721bc6e5c9173ef5276e716b1dd1b8d511c808fd9e5cb073b62e49ef08f0cf3
• Download URL:
  https://stacks.cdc.gov/view/cdc/221365/cdc_221365_DS1.pdf
• File Type:
  [PDF - 2.36 MB ]