Draft Method of Test for Flue Gas Composition (ORSAT Method) (NIEA A003.72C)

This method applies to the determination of carbon dioxide, oxygen, and carbon monoxide in flue gas from emission ducts, for samples with a total gas volume concentration of 0.2% to 30%. Testing personnel shall introduce a fixed volume of sample gas into an Orsat apparatus, sequentially absorb carbon dioxide, oxygen, and carbon monoxide using absorbents, and calculate the volume percentage of each component and the dry molecular weight of the gas from the readings. The method specifies sampling locations, line purging, direct on-site testing, apparatus leak checks, reagent preparation, and verification using standard gas, and sets limits for repeat-analysis errors and deviations from standard-gas concentrations. Acid gases, nitrous oxide, ammonia, and unsaturated hydrocarbons may cause interference.