This document specifies the test equipment and the test methods used for measuring the gravimetric efficiency and resistance to air flow of air filter for general ventilation. It is intended for use in conjunction with ISO 16890-1, ISO 16890-2 and ISO 16890-4. The test method described in this document is applicable for air flow rates between 0,25 m3/s (900 m3/h, 530 ft3/min) and 1,5 m3/s (5 400 m3/h, 3 178 ft3/min), referring to a test rig with a nominal face area of 610 mm × 610 mm (24 in × 24 in). This document refers to particulate air filter elements for general ventilation having an ePM1 efficiency less than or equal to 99 % and an ePM10 efficiency greater than 20 % when tested as per the procedures defined in the ISO 16890 series. NOTE            The lower limit for this test procedure is set at a minimum ePM10 efficiency of 20 % since it is very difficult for a test filter element below this level to meet the statistical validity requirements of this procedure. This document does not apply to filter elements used in portable room-air cleaners.