BS EN ISO 16890-4:2016

1   Scope This part of ISO 16890 establishes a conditioning method to determine the minimum fractional test efficiency . It is intended for use in conjunction with ISO 16890‑1, ISO 16890‑2 and ISO 16890‑3, and provides the related test requirements for the test device and conditioning cabinet as well as the conditioning procedure to follow. The conditioning method described in this part of ISO 16890 is referring to a test device with a nominal face area of 610 mm × 610 mm (24 inch × 24 inch).

  [ISO 16890](/search?q=ISO%C2%A016890)
   (all parts) refers to particulate air filter elements for general ventilation having
  an  e PM 1  efficiency less than or equal to 99 % and an   e  PM 10  efficiency greater than 20 % when tested according to the procedures defined within
  [ISO 16890](/search?q=ISO%C2%A016890) (all parts). 

    NOTE  The lower limit for this test procedure is set at a minimum  e PM 10  efficiency of 20 % since it will be very difficult for a test filter element below
     this level to meet the statistical validity requirements of this procedure. 

Air filter elements outside of this aerosol fraction are evaluated by other applicable
  test methods. See [ISO 29463](/search?q=ISO%C2%A029463) (all parts). 
Filter elements used in portable room-air cleaners are excluded from the scope of
  this part of [ISO 16890](/search?q=ISO%C2%A016890). 
The performance results obtained in accordance with [ISO 16890](/search?q=ISO%C2%A016890) (all parts) cannot by themselves be quantitatively applied to predict performance
  in service with regard to effic...