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Gas Sampling - Manual

Gases in most stacks or ducts often are comprised of small amounts of volatile, potentially toxic compounds in addition to major gas components such as nitrogen, oxygen, and carbon dioxide. At parts per million levels, most compounds with boiling points below that of water exist in a vapor state. Because gases generally are considered to be well mixed, sampling for constituents in the vapor phase usually is done through a simple probe from a single point of average gas velocity in the stack.

Gas sampling requires an understanding of Methods 1 through 3, these are basic methods of collecting a sample. Apex offers source sampling solutions to complete your testing needs. Apex Instruments consoles are designed to extract and trap the samples needed to test for harmful gases.  After the sample is collected there are many types of analysis depending on the compound(s) of interest.

A glass wool plug or filter is often necessary to screen out particulate matter from the gas stream, prior to collection in the vessel

  • Method 3 Gas Analysis for the Determination of Dry Molecular Weight
  • Method 3B Gas Analysis for the Determination of Emissions Rate Correction Factor of Excess Air
  • Method 4 Determination of Moisture in Stack Gases
  • Method 6 Determination of Sulfur Dioxide Emissions from Stationary Sources
  • Method 7 Determination of Nitrogen Oxide Emissions from Stationary Sources
  • Method 18 Integrated Bag Sampling for Organic Compounds
  • Method 26 Determination of Hydrogen Halide and Halogen Emissions
  • Method 0030 Volatile Organic Compounds (VOST)
  • Method 0031 Volatile Organic Compounds (SMVOC or SuperVOST)
  • Method 0040 Principle Organic Hazardous Constituents (POHCs) using Teldar Bags Method 0051 Hydrogen Chloride and Chlorine