Apparatus for Measuring Diesel Tailpipe Emissions in Underground Mines.

摘要

The U.S. Bureau of Mines and Michigan Technological University (MTU) are collaborating to develop an apparatus for measuring diesel tailpipe emissions in underground mines. A tailpipe emission measurement apparatus (EMA) is described that dilutes diesel exhaust and measures the concentrations of diesel particulate matter (DPM), CO, CO(2), NO, and NO(2) at known dilution ratios. The EMA was evaluated by side-by-side comparison of its measurements with those by laboratory-grade instruments. Concentration of CO and CO(2) measured by the EMA were usually plus or minus 14 percent of concentrations measured by laboratory-grade instruments for CO and plus or minus 20 percent for CO(2). EMA-measured DPM concentrations were, on average, 29 percent lower than those measured by laboratory-grade instruments, with the differences being fairly consistent. The CO and CO(2) differences are related to the method of calculating the EMA's dilution ratio, and the difference in DPM concentrations is attributed to thermophoretic and/or condensation losses related to the EMA's unheated sample probe. Preliminary analysis of data obtained with a heated sampling probe and modifications in the sampling procedures have indicated reduced variability in DPM and in the calculated dilution ratios.