AATCC 127:2017 pdf download.Water Resistance: Hydrostatic Pressure Test
1. Purpose and Scope
1.1 This test method measures the resistance of a fabric to the penetration of water under hydrostatic pressure. It is applicable to all types of fabrics, including those treated with a water resistant or water repellent finish.
1.2 Water resistance depends on the repcllency of the fibers and yarns, as well as the fabric construction.
1.3 The results obtained by this method may not be the same as the results obtained by the AATCC methods for resistance to rain or water spray.
1.4 This test method is performed without a restraint. If a restraint is required. use Test Method (TM) 208, Water Resistance: Hydrostatic Pressure Test Using a Restraint.
2. Principle
2.1 One surface of the test specimen is subjected to a hydrostatic pressure. increasing at a constant rate. until three points of leakage appear on its other surface. The water may be applied from above or below the test specimen.
2.2 This test is performed without a restraint.
10.2.1 In 1993. a limited interlaboratory study was completed, which included six laboratories, two operators in each, running determinations on three specimens of two fabrics. No prior assessment was made of the relative level of the participating laboratories on performance of the test method.
10.2.2 The two fabrics were at different levels (Fabric I approximately 810 mm and Fabric 2 approximately 340 mm), and residual variances of the two fabrics were found to be different. Accordingly, precision is reported separately for each fabric.
10.2.3 Users of the method arc advised of the limited nature of this study and advised to apply these findings with due caution.
10.2.4 Analysis of the data sets for each fabric yielded components of variance and critical differences as displayed in Tables 1, II and Ill. Differences between two averages of (N) determinations. for the appropriate precision parameter, should reach or exceed the table value to be statistically significant at the 95% confidence level.AATCC 127 pdf download.