Back in the late 1990’s, a close colleague and friend Dr. Paul Baron developed the “Aerosol Calculator” — an Excel spreadsheet that contained pretty much every equation imaginable (at the time) related to airborne particle behavior.
The Aerosol Calculator became legend, and an essential tool for anyone working in aerosol science. It contained over 100 equations for calculating aerosol behavior, drawing from the books Aerosol Measurement (edited by Baron and Willeke, and later Kulkarni, Baron and Willeke), and the equally legendary Aerosol Technology by Bill Hinds.
In recent times, it’s become increasingly hard to find copies of the Aerosol Calculator online, and sadly Paul Baron passed away some years ago, meaning that the resource hasn’t had a champion.
However, given renewed interest in aerosol behavior around coronavirus, I thought it useful to repost the original Aerosol Calculator, which also comes with some nifty spreadsheets for playing around with aerosol size distributions.
A Zip file containing various Calculator-related files can be downloaded here – the main file is “AEROCALC-Oct-1-01.XLS”
The spreadsheet also contains most of the equations included in the Aerosol Dynamics lecture notes I posted recently, and is useful for calculating everything from settling velocity with particle size to aerosol clearance rates in rooms — vital stuff when estimating exposure to coronavirus-containing particles in enclosed spaces.
By way of background, I worked with Paul from around 1992 on, first as a collaborator while I was working with the Health and Safety Laboratory in the UK, and later as a colleague at NIOSH in the US. As well as working together on a variety of aerosol sampler projects, we were the first people to publish on carbon nanotube exposure measurements back in the early 2000’s. With his passing in 2009, the international aerosol community lost one of its most respected members.
Update: Time has clearly passed faster than I realized — Paul started developing the Aerosol Calculator and soliciting feedback from users as far back as the 1980’s, as he explains in this 2006 abstract from the Seventh International Aerosol Conference in St. Paul MN.
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[…] Figure 1. Aerosol settling velocity as a function of particle size, assuming spherical particles with a density of 1000 kg/m3, an air temperature of 293.15 K, and an air pressure of 101.3 kPa. Drawing on Hinds (1999) and Baron (2001) […]