Filterefficiency (= efficiency of the filter at the retention of particles) is described by various descriptions which are defined by the manufacturer. There is no agreed directive.

Efficiency is stated as:

  • nominal
  • absolute
  • as beta ratio ß

Nominal

     90% - 98% of particles with the stated micron size and larger will be removed.

Absolute

     99% - 99,98% of particles with the stated micron size and larger will be removed.

Beta

     Ratio of influent particle count greater than size versus effluent particle count.

Beta
Beta
Beta
Beta
Beta
50
100
1000
5000
10000
 = 98%
= 99%
= 99,9%
= 99,98%
= 99,99%

( 1 - 1/ß) x 100