ISO 9237 Determination of Permeability of Fabrics to Air – Testing Equipment
7 ApparatusMetrological confirmation of the test apparatus shall be carried out in accordance with ISO 10012-1. 7.1 Circular specimen holder, with an orifice allowing the test to be carried out on an area of 5 cm2, 20 cm2, 50 cm2 or 100 cm2. The tolerance on the test area shall not exceed ± 0.5 %….