TOTEMS is a unique assembly of 20 instruments that have been chosen for their ability to quantify a suite of parameters associated with tailpipe emissions for improved real-world measurement and modal emissions modeling of light-duty vehicles. These parameters include tailpipe gas and particleconcentrations, exhaust flow rates, exhaust temperatures, sampling temperatures, vehicle position, engine operating behavior, ambient conditions, and instrumentation condition. Descriptions of each of the instruments are included in this paper. Unlike previous studies, this new instrumentation package collects, while the vehicle is traveling on the real-world road network: (i) the full number distributions of particle emissions using a particle spectrometer instrument that was not available previously; and (ii) quantifies mobile source air toxic (MSAT) gaseous emissions in addition tocriteria pollutant (CO, NOx, HC) and greenhouse gas (CO2, N2O) using a high-speed FTIR instrument specifically designed for on-board vehicle exhaust testing. Initial data sets have been collected for on-road driving in Chittenden County, Vermont, using a 1999 Toyota Sienna minivan. We will soon initiate year-long testing of two Toyota Camry study vehicles: one hybrid and one conventional. The sampling with these vehicles will include three-season, day-of-week, traffic peak and off-peak test periods. The Camry data will be used to build the first second-by-second, real-world gas and particle number emissions database for hybrid and conventional light-duty vehicles under cold climate and hilly terrain conditions experienced inVermont. This data will be modeled and ultimately lead to improved estimates of mobile source emissions at multiple scales (from project level to regional emissions estimates). In this paper we also examine a new tri-axial accelerometer for synchronous measurement of road grade for possible future inclusion in TOTEMS.
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