Investigation of Remote Sensing Devices for Chemical Characterization of Motor211 Vehicle Exhaust

摘要

The report summarizes results of tests to (1) evaluate the accuracy and precision211u001eof two different remote sensing devices (RSDs) for measuring carbon monoxide 211u001e(CO), hydrocarbons (HCs), and nitric oxide (NO), and (2) evaluating the 211u001ecapabilities of three RSDs for characterizing fleet emissions of NO. 'Puff' tests 211u001e(in which simulated motor vehicle exhaust gas was repeatedly injected in bursts 211u001eor puffs into the RSDs) were conducted. The accuracy and precision of data from 211u001ethese measurements, which showed a generally linear response over a range of 211u001econcentrations, were in the order CO > HCs > NO. Subsequently, three vehicles 211u001ewere driven at constant speed on a dynamometer and on a test track. The average 211u001eemissions data measured by the three RSDs at the track, when compared to the 211u001edynanmometer emissions data (which were used as the standard), in general showed 211u001ejust the opposite result; i.e., NO > HCs > CO. However, the test track data 211u001eshowed a considerable amount of variation. The three RSDs were tested for several 211u001ehours on a freeway ramp in Raleigh, NC.