What is absolute filtration?
BETA RATING: PARTICLE FILTRATION. A reliable test procedure for liquid filtration efficiency must be repeatable, must yield accurate and comparative results, and must indicate how the filter will consistently perform. Such an evaluation procedure, The Multi-Pass Test, has been endorsed by THE NATIONAL POWER ASSOCIATION, THE AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI), AND THE INTERNATIONAL STANDARDS ORGANIZATION (ISO). It is considered by the filtration industry to be the most reliable procedure to measure liquid filtration efficiency. In the Multi-Pass Test, fluid is continuously injected in uniform amount of contaminate particles, then pumped through the filter being tested. Filtration efficiency is accurately determined by monitoring oil contamination levels upstream and downstream of the filter at regular intervals. An automatic particle counter verifies the actual number of particles greater than given sizes on the upstream side, and this is compared to the number of same size pa
