Abstract
A method is described for quantifying the reentrainment of exhaust air contaminants into a building's fresh-air supply system. The method relies on the “tracer” gas, sulfur hexafluoride (SF6), which is detected by infrared (IR) absorption analysis. This method of analysis differs from the conventional gas chromatography, electron capture detection method previously used to detect SF6 in air. The IR method, using a MIRAN-1A Portable Gas Analyzer, may be superior to the conventional method due to the MIRAN-1 A's portability, direct-reading capabilities, ease of operation and modest cost. Specific instrument settings for the MIRAN-1A are given such that detection of SF6 will be optimized without interference. Calculations for quantifying reentrainment are presented and discussed for the “worst case” reentrainment observed.