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AN INVESTIGATION OF REMOTE SENSING DEVICES FOR CHEMICAL CHARACTERIZATION OF MOTOR VEHICLE EXHAUST
Citation:
Jones*, J., C. T. Ripberger*, AND N Vescio. AN INVESTIGATION OF REMOTE SENSING DEVICES FOR CHEMICAL CHARACTERIZATION OF MOTOR VEHICLE EXHAUST. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-98/170 (NTIS PB99-127987), 1998.
Impact/Purpose:
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Description:
The report summarizes results of tests to (1) evaluate the accuracy and precision of two different remote sensing devices (RSDs) for measuring carbon monoxide (CO), hydrocarbons (HCs), and nitric oxide (NO) and (2) evaluate the capabilities of three RSDs for characterizing fleet emissions of NO. In doing so, it lays the groundwork for analysis efforts that will be the basis for future articles. "Puff" tests (in which simulated motor vehicle exhaust gas was repeatedly injected in bursts, or puffs, into the RSDs) were conducted. The accuracy and precision of data from these measurements, which showed a generally linear response over a range of concentrations, were in the order CO>HCs>NO. Subsequently, three vehicles were driven at constant speed on a dynamometer and on a test track. The average emissions data measured by the three RSDs at the track, when compared to the dynamometer emissions data (which were used as a standard), in general showed just the opposite result; i.e., NO>HCs>CO. However, the test track data showed a considerable amount of variation. Whether or not this was caused by conditions at the site (e.g., only a slight grade, which made maintaining constant vehicle speed difficult) or some other variable is a question for possible future research. The three RSDs were tested for several hours on a freeway ramp in Raleigh, NC.