Remote sensing of particulate emissions from heavy-duty vehicles : final report on phase I

This report summarizes the results of initial tests of a remote sensing system capable of real-time detection of particulate emissions from heavy-duty transit vehicles under actual on-road operating conditions. The technique employs optical extinction (sometimes called opacity) to measure concentrations of CO2 and soot in the exhaust plumes from individual vehicles. Two wavelength regions (bands) are used, one of which is sensitive to soot and the other of which is used to monitor CO, levels. From these two measurements, an emissions index can be computed which normalizes the mass of soot emitted by the amount of fuel burned. The primary goal of phase I was ascertain whether the new technique held promise of sufficient sensitivity and accuracy for on-road deployment.