Development of a Portable Remote Sensing System for Measurement of Diesel Emissions from Passing Diesel Trucks

A wireless remote-sensing system has been developed for measurement of NOx and particulate matters (PM) emissions from passing diesel trucks. The NOx measurement system has a UV light source with quartz fiber optics that focused the light source into a spectrometer. The signals from the spectrometer was routed through a wireless antenna to a remote computer and NOx measurements were performed by comparing the spectra of the receiving signals to a reference spectrum for compliance. Results of the remote sensing system were compared with direct exhaust measurements. For NOx measurement, comparing the variance of the spectrum between the 200-300 nm wavelengths with direct diesel engine exhaust measurement, an approximate NOx/variance ratio of 0.5 was found for the stationary measurement and ratios of 0.3-0.4 were obtained for transient measurements. PM measurements were performed by both a TSI DustTrak model 8520 and a remote MiniPCS particle counter-sizer system from Measurement Science Enterprise (MSE). Results of the PM measurements from these devices were comparable, indicating the potential of the MiniPCS system for remote sensing PM measurements.