Research in the 1920s and 1930s identified what appeared to be a new type of Rickettsia, isolated from ticks, that was able to pass through filters.
The Microparticle Performance Rating (MPR) system rates an Air filter’s ability to capture the smallest airborne particles—from 0.3 to 1 µm in size from the air passing through the filter.
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Some newer vacuum cleaners have high-efficiency particulate air filtration (HEPA) filters attached, which, when combined with the special bags, are effective in trapping almost 100% of allergens, including ragweed, dust mites, and grass pollen.
National Safety Associates (NSA) is a privately owned marketing company based in Collierville, Tennessee, best known for selling a line of water and air filters, and then the nutritional supplement Juice Plus, via multi-level marketing.
Carburetor Heat Control - Controls the application of heat to the carburetor venturi area to remove or prevent the formation of ice in the throat of the carburetor as well as bypassing the air filter in case of impact icing.
Notable race modifications from the passenger car engine include a re-chipped ECU supplied by GM India, K&N Air filter and tuned Free flow Exhaust pipes while the Head, Block and Camshaft remained the same as in Stock.
HEPA, a high efficiency particulate arresting air filter