ASTM D737-96 pdf free.Standard Test Method for Air Permeability of Textile Fabrics.
Test Specimens- -F rom each laboratory sampling unit, take ten specimens unless otherwise agreed upon between purchaser and supplier, Use the cutting die or template described in 6.2, or if practical, make air permeability tests of a textile fabric without cuting
Cutting Test Specimens- -When cutting specimens, cut having dimensions at least equal to the area of the clamping mechanism. Label to maintain specimen identity. Take specimens or position test areas representing a broad ditribution across the length and width, preferably along the diagonal of the laboratory sample, and no nearer the edge than one tenth its width unless otherwise agreed upon between the purchaser and supplier. Ensure specimens are free of folds, creases, or wrinkles. Avoid getting oil, water, grease, and so forth, on the specimens when handling.
Preparation of Test Apparatus and Calibration. Set-up procedures for machines from different manufacturers may vary. Prepare and verify calibration of the air permeability tester as directed in the manufacturer’s instructions.
When using microprocessor automatic data gathering systems, set the appropriate parameters as specified in the manufacturer’ s instructions.
For best results, level the test instrument.
Verify calibration for the range and required water pressure differential that is expected for the material to be tested.
Precondition the specimens by bringing them to approx imate mois ture equilibrium in the standard atmosphere for preconditioning textiles as specified in Practice D 1776. After preconditioning, bring the test specimens to moisture equilibrium for testing in the standard atmosphere for testing textiles as specified in Practice D 1776 or, if applicable, in the specified atmosphere in which the testing is to be performed.
When it is known that the material to be tested is not affected by heat or moisture, preconditioning and conditioning is not required when agreed upon in a material specification or contract order. ASTM D737 pdf download.