A Dynamic Gas-Mixing System

Details

• Personal Author:
  Carpenter, Clarence R. ; Chilton, Joseph E. ; Schnakenberg, George H. Jr.
• Description:
  A dynamic gas-mixing system assembled by the Bureau of Mines for the generation of precise gas mixtures from sources of concentrated or pure gases and diluent gases is described. A set of electronic mass flow controllers with maximum flows ranging from 10 to 5,000 ml/min, a so-called pure air generator, and gases in cylinders are used to generate differing gas concentrations. The repeatability of the delivery rate of a flow controller, measured on different days, has a precision of 0.3 pct of the setting. This dynamic gas-mixing system reduces the cylinder inventory and the demurrage charges for special gas mixtures. Gas mixtures that cannot be shipped commercially, such as flammable mixtures of methane in air, can be conveniently prepared by this system. The maximum dilution ratio is 2.5 X 10 4. Thus, gas mixtures can be made over a wide range of concentrations, from the percent region (by dilution of a pure single-component gas) to fractional parts per million (by dilution of a premixed standard, e.g., a 1,000-ppm mixture). This system is especially useful in determining the response of gas detection devices over the entire range of their measurement. Because the controllers are voltage controlled they lend themselves easily to automated control using computer-based systems. [Description provided by NIOSH]
• Subjects:
  Carbon Monoxide Hydrogen Sulfide Occupational Health Oxygen Safety
• Keywords:
  Mining-engineers; Chemical-dosimeters; Binary-systems-materials; Performance-evaluation; Design-criteria; Safety; Carbon-monoxide; Nitrogen-oxide-NO; Nitrogen-dioxide; Sulfur-dioxide; Hydrogen-sulfide; Oxygen; Methane; Carbon-dioxide; Automatic-control-equipment
• Series:
  Mining Publications
• Subseries:
  Information Circular
• Document Type:
  Text
• Genre:
  Conference Publications ; Pamphlet or Booklet
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRC - Pittsburgh Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-30
• NIOSHTIC Number:
  nn:10003015
• NTIS Accession Number:
  PB84-101450
• Citation:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 8934, 1983 Aug; :1-30
• Federal Fiscal Year:
  1983
• Peer Reviewed:
  False
• Source Full Name:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, IC 8934
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f9ef0dedab18bf2dce3c60915f35040d83252afd3d9edc1e1c9903fbd073f2b4bc971b46a40d6d0a103403cf0f8151f724e3d835ba09db19e6981154958c37b8
• Download URL:
  https://stacks.cdc.gov/view/cdc/235558/cdc_235558_DS1.pdf
• File Type:
  [PDF - 1.43 MB ]