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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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Mobile Laboratory Mounted Fast Response Instrument Methods for On-Road Vehicle Emissions Measurements
C.E. Kolb, S.C. Herndon, J.B. McManus, J.H. Shorter, M.S. Zahniser,
D.D., Nelson, J.T. Jayne, M.R. Canagaratna, and D.R. Worsnop
Aerodyne Research, Inc., Billerica, MA 01821-3976
B.K. Knighton
Department of Chemistry, Montana State University, Bozeman, MT 59717
E. Dunlea, M. Zavala, L.T. Molina, and M.J. Molina
Department of Earth, Atmospheric and Planetary Sciences
Massachusetts Institute of Technology, Cambridge, MA 02139
The development of sensitive, rugged, fast response (<1 to 3 s) instrumentation allows the real-time, on-road characterization of gaseous and fine particulate motor vehicle emissions using mobile laboratory methods. Trace gaseous emissions of CO, H2CO, NO, NO2, HONO, NH3, SO2, CH4, C2H2, C2H4, and C2H6 can be measured by tunable infrared laser differential absorption spectrometers (TILDAS) while selected oxygenated (CH3OH, CH3CHO) and aromatic (benzene, toluene, xylenes) VOCs can be quantified by proton transfer reaction mass spectrometry (PTR-MS). The non-refractory chemical components of fine exhaust particles can be determined as a function of particle size on time scales a short as 2 s by sampling and analyzing exhaust plumes using aerosol mass spectrometry (AMS) techniques. Exhaust plume CO2, total nitrogen oxide content (NOy), and total fine particle number density and surface area can all be monitored with 1 s resolution using instruments that have been commercially available for some time. The use of these sampling instruments aboard a mobile laboratory deployed in both on-road survey and vehicle chase modes to characterize and quantify fleet and individual vehicle emissions in urban environments and on highways will be presented. Recent data for vehicles from Mexico City and New York City will be highlighted.