- BenLv 71 decade agoFavorite Answer
"K&N Air Filter Efficiency Testing
The air filter industry uses the ISO 5011 testing protocol when testing filtration efficiency and dust capacity. The test protocol calls for the introduction of a measured amount of “test dust” into the air filter at a selected airflow rate. The test is then terminated after the filter reaches a selected level of restriction (terminal test pressure). The test protocol then measures the percentage of dust retained by the filter (efficiency) and the total amount of dust held by the filter (capacity)."
The rest of the article is here at the K & N website
More about the K&N air filter can be found in the first Source below.
BenSource(s): K&N ISO 5011 TEST http://www.google.com/#sclient=psy&hl=en&q=K%26N+I... ISO 5011 TEST http://www.google.com/#sclient=psy&hl=en&q=ISO+501...