Air permeability is the property of a fabric to allow passage of air through it under the effect of a difference in pressure across its two faces. It is defined as the volume of air passing through a defined area under a specified pressure difference over a known period of time. It is a very important property for fabrics that are used under conditions where it is necessary to know precisely the amount of air passing through them.
Test area : 10, 20, 50, and 100 cm²
Rotameters : 9 to 90; 57 to 570; 470 to 4,700; and 1,570 to 15,700 LPH
Pressure indicator : Electronic type with a pressure transducer and digital display to measure and indicate pressure upto 300 mm water column (least count 1 mm)
IS 11056 - 1984 : Method for Determination of Air Permeability of Fabrics
DIN 53887 : Testing of Textiles - Determination of the Air Permeability of Fabrics
ASTM D 737 : Standard Test Method for Air Permeability of Textile Fabrics.