Characteristics of an Aerosol Photometer While Automatically Controlling Chamber Dilution-Air Flow Rate

Details

• Personal Author:
  Hemenway DR ; O'Shaughnessy PT
• Description:
  Trials were conducted to determine those factors that affect the accuracy of a direct-reading aerosol photometer when automatically controlling airflow rate within an exposure chamber to regulate airborne dust concentrations. Photometer response was affected by a shift in the aerosol size distribution caused by changes in chamber flow rate. In addition to a dilution effect, flow rate also determined the relative amount of aerosol lost to sedimentation within the chamber. Additional calculations were added to a computer control algorithm to compensate for these effects when attempting to automatically regulate flow based on a proportional-integral-derivative (PID) feedback control algorithm. A comparison between PID-controlled trials and those performed with a constant generator output rate and dilution-air flow rate demonstrated that there was no significant decrease in photometer accuracy despite the many changes in flow rate produced when using PID control. Likewise, the PID-controlled trials produced chamber aerosol concentrations within 1% of a desired level. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Automation Dust Occupational Health Particulate Matter Safety
• Keywords:
  Aerosol-particles Aerosol-sampling Airborne-dusts Dust-exposure Equipment-design Exposure-chambers Exposure-levels Mathematical-models
• ISSN:
  0895-8378
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 1 ; Vermont
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  12
• Issue:
  10
• NIOSHTIC Number:
  nn:20029858
• Citation:
  Inhal Toxicol 2000 Oct; 12(10):979-996
• Contact Point Address:
  Department of Occupational and Environmental Health, University of Iowa, 100 Oakdale Campus, #180 IREH, Iowa City, IA 52242-5000
• Email:
  patrick-oshaughnessy@uiowa.edu
• Federal Fiscal Year:
  2001
• Performing Organization:
  University of Vermont & St Agric College, Burlington, Vermont
• Peer Reviewed:
  True
• Start Date:
  19940401
• Source Full Name:
  Inhalation Toxicology
• End Date:
  19960331
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:2ba6971ad4da47b5ca767a956b2cd35d31bbc45dfcd24247c2c6d08cc4ca3c71575b73079eb577c2b8bc7cc2beaefccf75adb08b7c07a7795602f28d05df953b
• Download URL:
  https://stacks.cdc.gov/view/cdc/190761/cdc_190761_DS1.pdf
• File Type:
  [PDF - 457.09 KB ]