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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Poster 10: The Development Of Real World Emissions Inventories Using Portable Vehicle Emissions Monitors (PEMS)
Michal Vojtisek-Lom, P. Joshua Wilson, Tom Albrechcinski
Clean Air Technologies International, Inc., Buffalo, New York, 14211
In the past, the traditional development of vehicle emissions data bases and fleet inventories has been based on laboratory measurements of representative vehicles using chassis dynamometer driving cycles representative of projected driving patterns. These measurements are relatively expensive, limited in scope, and are not necessarily representative of vehicles in actual operation on and off road.
In recent years the development and use of Portable Emissions Monitoring Systems (PEMS) have opened new possibilities for the quantitative, accurate measurement of vehicle emissions under real world operating conditions. The use of PEMS are becoming increasingly accepted for use by federal, state and private agencies for the efficient, economical, accurate and representative measurement of vehicle emissions.
The OEM-2100 Montana system, manufactured and used by Clean Air Technologies and several university and other research groups, has been used to measure real-time particulate and gaseous (HC, CO, CO2 and NOx) emissions on fleets of cars, trucks, commuter vans, school and transit buses, delivery vans, construction equipment, ferry boats, and other equipment. This data was used to quantify the overall fleet emissions, to evaluate the impact of advanced technologies, alternative fuels and exhaust gas aftertreatment devices, but also the impact of traffic signal optimization, traffic pattern improvements, driving style, extended idling of heavy-duty trucks, and other means which are difficult to evaluate using traditional laboratory testing.
The results of these studies demonstrated that the emissions from vehicles having presumably like engines and performance can vary significantly. Therefore, relative to laboratory studies, on road real world measurements have the distinct advantage of providing more representative assessments of fleet total and regional total emissions inventories relative to limited laboratory studies.