Salon: “The number on all of those refers to its filtration efficiency, so the percentage of articles that it stops from getting through,” said Dr. John Volckens, a professor of Mechanical Engineering at Colorado State University.
linkSalon: “The number on all of those refers to its filtration efficiency, so the percentage of articles that it stops from getting through,” said Dr. John Volckens, a professor of Mechanical Engineering at Colorado State University.
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