A “MAGIC” Method for Airborne Particle Measurement
Susanne V. Hering
Aerosol Dynamics Inc.
Ultrafine, airborne particles are important to human health and the environment, yet direct measurement is difficult, as most are too small to detect or size optically. For decades, aerosol scientists have circumvented this issue through alcohol-based condensational enlargement – turning each small particle into a micrometer sized droplet. Our approach accomplishes this droplet formation using water instead of alcohol. Referred to as moderated aerosol growth with internal water cycling, our method consumes almost no water, instead stealing the water needed for condensation from the air itself. One of our MAGIC condensation particle counters was adapted to micro-gravity. Launched in October 2020, it is now returning data on the particle concentrations in the air the astronauts breathe aboard the International Space Station. Another version has been miniaturized as a wearable particle sensor, and yet a third versions has been adapted as the detector in a compact, mobility particle sizing system.
After earning her PhD in Physics from the University of Washington, Susanne Hering began her studies of atmospheric aerosols through postdoctoral studies at Caltech. She founded Aerosol Dynamics Inc. in 1991, where she and her group have focused on the development of new instruments for airborne particle characterization. Of note are an on-line method for characterizing the organic constituents of airborne particles, developed in collaboration with University of California, Berkeley; a viable aerosol collector developed in collaboration with the University of Florida, and as well as the water-based condensation particle counting presented here.