ISO 811: ISO 811 (耐静水压试验)
An international standard for measuring the resistance of fabrics to water penetration under increasing hydrostatic pressure. The specimen is clamped over a water column and pressure is raised until droplets appear, giving a value in centimetres or pascals. For waterproof zippers it verifies that tapes, films and sealed seams resist rain and pressure. Sample preparation, temperature and rate of pressure rise affect results, so conditions are strictly controlled.