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NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
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Tower Based Real Time Monitoring System for Quantifying Fugitive Emissions
J.A. Gillies, H. Kuhns, V. Etyemezian, D. Nikolic, H. Moosmüller, and W.P. Arnott
Division of Atmospheric Sciences, Desert Research Institute, Reno and Las Vegas, NV
A multi-tower measurement system incorporating real-time particulate matter (PM) mass concentration, particle sizing, and meteorological instruments to quantify mass fluxes and emission factors for fugitive emissions is presented. The system can also integrate collocated real-time visibility measurements for regional haze emissions assessments. The three 12-m towers are equipped with up to 16 TSI DustTraks (4 to 6 per tower) to measure mass concentration (PM10, PM2.5, or PM1) at multiple heights above ground level. GRIMM model 1.108 Particle Sizers are used to obtain particle size distributions (0.4-20 µm) of the emitted PM. The towers can be placed at varying distances downwind of the source to characterize deposition and dispersion of the emissions. Visibility instruments that have been integrated into the system include the DRI photoacoustic instrument (light absorption), integrating nephelometer (light scattering), and cavity ring-down extinction meter. Data acquisition is accomplished with a network of portable computers running a custom-designed LabView program that synchronizes data collection and writes the acquired data to a Microsoft Access compatible database. Instrument sampling rates are typically 1 Hz. Data are visualized in real-time, which provides an important first level of quality assurance and control.
This system has been used to measure PM10 emissions and to develop emission factors for civilian and military vehicles traveling on unpaved roads at Ft. Bliss, TX. The multi-tower network has also been used to assess near source dust deposition and removal processes for fugitive dust plumes advecting over a sparsely vegetated desert surface. A modified single-tower has been used to measure PM10 and PM2.5 fluxes from vehicle exhaust and resusepended road dust for paved roads.