ALEXANDRIA, Va., Sept. 17 -- United States Patent no. 12,416,582, issued on Sept. 16.
"Particulate matter detection device" was invented by Christopher Lee Boortz (Aurora, Colo.), Jack Matthews (Aurora, Colo.) and Shahbaz Hussain (Aurora, Colo.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A particulate matter detection device and methods for detecting a particulate matter in the environment. The particulate matter detection device comprising an indicator comprising a detection layer, an optical substance bonded to a detection layer surface, and a graphical target layer viewable through one or more apertures in the detection layer. The adsorption of particulate matter to the optical substance obscures the g...