Part 1: Classification, performance testing, marking
As decided by CEN/TC 195, this European Standard is based on particle counting methods which
actually cover most needs of different applications. The difference between this European Standard and previous national standards lies in the technique used for the determination of the integral efficiency.
Instead of mass relationships, this technique is based on particle counting at the most penetrating particle size (MPPS), which is for micro-glass filter mediums usually in the range of 0,12 µm to 0,25 µm.
For Membrane filter media, separate rules apply, see Annex A of EN 1822-5:2009. This method also
allows testing ultra low penetration air filters, which was not possible with the previous test methods
because of their inadequate sensitivity.
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