Vehicle mass emissions measurements using a portable 5-gas exhaust analyzer and engine computer data

摘要: The University of Pittsburgh commuter vanpool operates 20 dedicated compressed natural gas vans. Data on fuel use, maintenance, oil contaminants, and tailpipe emissions these vans are collected. A method is being developed to determine “real-world” mass using an on-board low-cost fivegas non-dispersive infra-red exhaust analyzer, engine diagnostic scanner a laptop computer. computer uses live port data compute molar flow, which, when multiplied by molecular weight measured concentrations gases, yields grams per second data. Grams mile calculated from known distance time the trip. $10,000 system, also capable measuring consumption, portable, requires no modifications vehicle, commercially available instruments. Although system consistent 8-mile test route, values during I/M 240 tests show correlations 0.67 for NOx, 0.50 HC 0.68 CO between portable instruments high test-to-test differences. Others have found good correlation analyzer emission. poor in this study may be attributed extremely low (tenths percent instrument range) tested vehicles. Improving accuracy focus ongoing research.