Advance Notice for the Repeal of "Method for Determining Gas Composition in Emission Ducts‑Orsat Method (NIEA A003.71C)"

This method applies to determining the volume percentages of carbon dioxide, oxygen, and carbon monoxide in stationary source gases, for samples with a total gas volume concentration of 0.2% to 30%. An Orsat apparatus shall be used to sequentially absorb carbon dioxide, oxygen, and carbon monoxide with absorbents, and readings shall be used to calculate component concentrations and dry-basis molecular weight. The sampling system shall be airtight and adequately purged, and testing shall generally be conducted on site; leak checks shall be completed before analysis, absorbent capacity shall be adequate, and repeat-analysis errors and daily oxygen verification values shall meet specified requirements. As the method no longer meets practical testing needs, its repeal has been announced in advance and its content has been incorporated into the draft NIEA A003.72C.