The impact penetration tester is used to determine the resistance of a fabric to the penetration of water by impact, and thus can be used to predict the probable resistance of the fabric to rain penetration. Suitable for measuring the penetration resistance of garment fabrics and e.g. umbrellas, the test has also been adopted by the medical industry as a measure of liquid barrer performance for protective apparel and drapes.
A test specimen is mounted tautly, face-up on an angled surface. A pre-weighed sheet of blotter paper is mounted behind the specimen. A volume of water is sprayed against the face of the specimen. The blotter paper is then re-weighed to determine water penetration. The increase in mass of the blotter paper indicates the mass of water that passed through the test specimen.