Sequential and tape samplers

Details

• Personal Author:
  Perry WH
• Description:
  All tape samplers use tape as the collecting medium. The tape may be advanced periodically to produce a circular spot or a band which represents an integrated sample. This sample can be evaluated at the end of the sampling period to give a time-weighted average for that period. This manner of operation produces a series of discrete values. A sampler operating in this way could be considered as a type of sequential sampler. It is, however, customarily referred to as a tape sampler. The sample collected by periodic tape advance can be evaluated continuously as sampling proceeds. For example, reflected light can be monitored using a reflectometer contained in the sampling head. The rate of darkening of the spot is related to the concentration of the contaminant in the air sample. The cumulative change is related to the time-weighted average. By equipping such a sample with a recorder it becomes a direct reading continuous monitor. Some tape samplers are designed for continuous tape advance. The sample appears as a trace of gradually changing appearances or as a series of spots or bands. If the contaminant concentration changes gradually, the sample appears as a trace. If the concentration changes are abrupt, the tape resembles one produced by periodic movement. Continuous advance is suggested for monitoring of high concentrations such as may be found in mines, road tunnels, or in stack monitoring. Tapes obtained by continuous movement may be evaluated concurrently with collection. Such samplers are also direct reading continuous monitors. It may be necessary to delay evaluation until sampling has been completed and perhaps the tape has been removed from the sampler. It is still possible to obtain a profile of the concentration even though it is not in real-time. Such a system can be thought of as a delayed-reading continuous monitor. In most tape samplers the air sample passes through the tape. Particulate matter is collected by filtration. Tapes impregnated with chemical reagents are used in the determination of gases and vapors. Sometimes the air sample passes over the surface of the tape rather than through it. The tape is very often composed of paper but plastic filtration membranes, glass fiber, and other materials are also used. The tape must have sufficient mechanical strength and have purity and other physical and chemical properties consistent with both sampling and analytical needs. [Description provided by NIOSH]
• Subjects:
  Environmental Monitoring Occupational Health Safety
• Keywords:
  Air-quality-measurement Air-quality-measurement-equipment Air-samplers Air-sampling-equipment Analytical-instrumentation Analytical-methods Measurement-instrumentation Measuring-equipment Sampling-equipment
• Publisher:
  American Conference of Governmental Industrial Hygienists (ACGIH)
• Document Type:
  Text
• Genre:
  Book
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DTMD - Division of Training and Manpower Development
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20049143
• Citation:
  Air sampling instruments for evaluation of atmospheric contaminants, 5th edition. Cincinnati, OH: American Conference of Governmental Industrial Hygienists (ACGIH), 1978 Jan; :M-1--M-32
• Contact Point Address:
  William H. Perry, CIH, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226
• Federal Fiscal Year:
  1978
• Peer Reviewed:
  False
• Source Full Name:
  Air sampling instruments for evaluation of atmospheric contaminants, 5th edition
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e7a7e2023d8b7d02242c0af61901e27921a6792073807d2e4068ebaa0e80f719ce913d269f965a4ae4d2342f6ddd4da18a0e962726c3f220f3bffe7e3b010913
• Download URL:
  https://stacks.cdc.gov/view/cdc/203698/cdc_203698_DS1.pdf
• File Type:
  [PDF - 14.82 MB ]