Small Business	Research Institution
Aerosol Dynamics, Inc. 2329 Fourth Street Berkeley, CA 94710-2401 Dr. Susanne Hering, Principal Investigator Dr. Susanne Hering, Business Official (510) 649-9360	University of Denver (Colorado Seminary) 2199 South University Boulevard Mary Reed Building, Room 222 Denver, CO 80208

Fine airborne particles contribute to urban haze, impair atmospheric visibility in our national parks, influence global climate, and may impair human health. Knowledge of their composition and concentration is limited for lack of suitable monitoring technology. There is a critical need for instruments that provide automated, high time-resolution measurement of the chemical composition and light scattering coefficient of these particles as a function of their size. This project will develop a modular system that will provide immediate data on: (1) the airborne concentration of sulfates, nitrates, and carbonaceous aerosols in three size classes and, (2) the particle size distribution and light scattering coefficient in thirty-two size channels. The chemical composition of the particles will be measured with a time resolution of 10 minutes, and particle size and scattering will be measured optically with a time resolution of 30 seconds. An integrated collection and flash-vaporization method was recently developed for the automated, high-time resolution measurement of fine particle nitrate concentrations. Phase I will determine the feasibility of extending this approach to sulfate and carbonaceous aerosols through laboratory and field testing. Additionally, the use of single particle scattering measurements will be validated for determining the size-resolved light scattering coefficient.

Commercial Applications and Other Benefits as described by the awardee: Commercial applications include routine monitors for air quality districts, and specialized monitors for research studies on urban particulate air quality, regional visibility, epidemiology and global climate.