Characterization of a Multi-Stage Focusing Nozzle for Collection of Spot Samples for Aerosol Chemical Analysis (Dataset)

Details

• Corporate Authors:
  National Institute for Occupational Safety and Health
• Description:
  Download the Dataset decsribed here from Data.cdc.gov at https://doi.org/10.26616/NIOSHRD-1074-2023-0. ; Concentrated collection of aerosol particles on a substrate is essential for their chemical analysis using various microscopy and laser spectroscopic techniques. An impaction-based aerosol concentration system was developed for focused collection of particles using a multi-stage nozzle that consists of a succession of multiple smooth converging stages. Converging sections of the nozzle were designed to focus and concentrate a particle diameter range of 900 to 2500 nm into a relatively narrower particle beam to obtain particulate deposits with spot diameters of 0.5-1.56 mm. A slightly diverging section before the last contractions was included to allow for better focusing of particles at the lower end of the collectable diameter range. The characterization of this multi-stage nozzle and the impaction-based aerosol concentration system encompassing the nozzle was accomplished both numerically and experimentally. The numerical and experimental trends in collection efficiency and spot diameters agreed well qualitatively; however, the quantitative agreement between numerical and experimental results for wall losses was poor, particularly for larger particle diameters. The resulting concentrated particulate deposit, a spot sample, was analysed using Raman spectroscopy to probe effect of spot size on analytical sensitivity of measurement. The method's sensitivity was compared against other conventional techniques, such as filtration and aerosol focused impaction, implementing condensational growth. Impaction encompassing the multi-stage focusing nozzle is the only method that can ensure high sensitivity at Reynolds numbers greater than 2000, that can be supported by small pumps which renders such method suitable for portable instrumentation. Description provided by NIOSH
• Subjects:
  • Aerosols
  • Chemistry
  • Microbiology
  • Occupational Health
  • Particulate Matter
  • Safety
• Keywords:
  • Aerosols
  • Aerosol sampling
  • Spectroscopes
  • Microscopic analysis
  • Analytical instrumentation
  • Chemical analysis
  • Particle size
• Series:
  NIOSH Data
• DOI:
  https://doi.org/10.26616/NIOSHRD-1074-2023-0
• Landing Page:
  https://stacks.cdc.gov/view/cdc/207124
• Dataset Download URL:
  https://data.cdc.gov/download/rdfw-s4u4/application%2Fx-zip-compressed
• Identifier:
  https://doi.org/10.26616/NIOSHRD-1074-2023-0
• Format:
  ZIP folder
• Document Type:
  Dataset
• Genre:
  Research Dataset
• Place as Subject:
  OSHA Region 3 ; West Virginia
• Media Type:
  application/zip
• Described By Type:
  HTML Repository Page
• License:
  https://creativecommons.org/public-domain/
• Rights:
  Public Domain
• Described By:
  https://stacks.cdc.gov/view/cdc/207124
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Contact Point:
  Health Effects Laboratory Division (HELD)
• Pages in Document:
  1 ZIP folder
• NIOSHTIC Number:
  nn:20068508
• Citation:
  Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Research Dataset RD-1074-2023-0, 2023 Dec; :dataset
• Email:
  sa-cin-webteam@cdc.gov
• Federal Fiscal Year:
  2024
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  False
• Download URL:
  https://stacks.cdc.gov/view/cdc/207124/cdc_207124_DS1.pdf
• File Type:
  [PDF - 170.66 KB]
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8742dd9d7d01da5092414a265c4bf6cc0d30cdeccd86e495854c8d73211c6fc4cc408112abd4e48dc2ce3a68db7cd29c6f549ed7bdc30a300e8e70b3851719f5