Further Observations of the Effect of Sample Probes on Pollutant Gases Drawn from Flame Zones

Abstract
The effects of gas sample probes and conditioning techniques on the measurements of flame- generated NO, NO2, and CO have been further examined. (1) A low-pressure, condensation free sampling system was compared with a conventional system, which operated at higher pressure and involved H2O condensation. The conventional system demonstrated apparent losses of CO and NOx, in the range 10 to 50 percent. (2) Sampling from fuel-rich combustion and pyrolysis zones was examined. High NO2-to-NO ratios, approaching unity, were measured repeatedly in the fuel-rich pyrolysis zone of a high-intensity recirculative flame.
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