With an onging SBIR presence beginning from soon after founding of the firm to the present day, Aerosol Dynamics Inc. produces measurement methods for characterizing fine airborne particles that comprise the visual haze in the atmosphere and are important to air quality, human health and global climate. The firm goal is to develop better methods and instrumentation for characterizing atmospheric aerosols for air quality monitoring, epidemiology studies and global climate research using water-based condensation particle counters and collectors, and in-situ instruments for aerosol chemistry. The firm has developed a gas chromatograph- mass spectrometry (GC-MS) system for atmospheric aerosols. This technology has been licensed to Aerodyne Research Inc. for incorporation into their Aerosol Mass Spectrometer as a dual inlet option (TAG-AMS). Example Chromatogram from TAG The system yields approximate hourly concentrations for organic marker compounds in atmospheric aerosols. Current efforts include improved quantification with in-situ calibration standards, and adaptation of two-dimensional chromatography for separation and analysis of polar compounds. Other patented technology from the firm has led to a family of instruments for measuring the number concentration of ultrafine and nanometer-sized airborne particles. Micro-Environmental WCPC Nanometer-sized particles are enlarged through water condensation in a thermally diffusive flow to form micrometer-sized droplets that can be counted optically; Particles as small as 3 nm (0.003 µm) can be detected.