ASTM D7520, Test Method for Determining the Opacity of a Plume in the Outdoor Ambient Atmosphere, was developed by Subcommittee D22.03 on Ambient Atmospheres and Source Emissions, part of ASTM International Committee D22 on Air Quality.

“This is a great story about how innovative technologies and techniques are developed with Department of Defense-supported research and they result in the development of new methods like ASTM D7520. The development of this new method to determine plume opacity with low-cost digital still cameras was initially described in peer-reviewed journals and conference proceedings and is now an approved ASTM standard to assist USEPA in improving air quality at lower cost and with less subjectivity”, says Mark J. Rood, Ph.D., Ivan Racheff Professor of Environmental Engineering, University of Illinois, and a D22 member.

“Currently, industry/government facilities and USEPA use human observers to quantify the opacity of plumes with USEPA Method 9,” says Rood. “This new method allows the use of digital cameras and software to determine plume opacity while also providing a digital image of the plume and its surrounding environment to improve our ability to report plume opacities for regulatory purposes”.

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