This International Standard is applicable to any textile fabric, which may or may not have been given a water-resistant or water-repellent finish. It measures the resistance of fabrics to the penetration of water by impact, and thus can be used to predict the probable rain penetration resistance of textile fabrics. It is especially suitable for measuring apparel fabrics. With the instrument, tests may be made at different intensities of water impact to give a complete picture of the penetration resistance of a single fabric or combination of fabrics. The test is particularly suitable when measuring highly water resistant fabrics with low amounts of water penetration.