This part of ISO16890 specifies the aerosol production, the test equipment and the test methods used for measuring fractional efficiency and air flow resistance of air filters for general ventilation. It is intended for use in conjunction with ISO16890‑1 , ISO16890‑3 and ISO16890‑4 . The test method described in this part of ISO16890 is applicable for air flow rates between 0,25m 3/s (900m 3/h, 530ft 3/min) and 1,5m 3/s (5400m 3/h, 3178ft 3/min), referring to a test rig with a nominal face area of 610mm×610mm (24,0 inch×24,0 inch). ISO16890 (all parts) refers to particulate air filter elements for general ventilation having an ePM 1 efficiency less than or equal to 99%and an ePM 10 efficiency greater than 20%when tested as per the procedures defined within ISO16890(allparts) . NOTE The lower limit for this test procedure is set at a minimum ePM 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 ISO29463 (all parts)). Filter elements used in portable room-air cleaners are excluded from the scope. The performance results obtained in accordance with ISO16890 (all parts) cannot by themselves be quantitatively applied to predict performance in service with regard to efficiency and lifetime.