AATCC 42-2000 Water Resistance: Impact Penetration Test

AATCC 42-2000 Water Resistance: Impact Penetration Test.
8. Evaluation
8.1 The increase in mass of the blotter in grams is calculated and the average re- sult of the three test specimens is reported. Individual determinations or average values of over 5.0 g may be simply reported as + 5.0 g or > 5.0 g.
9. Report
9.1 Report the individual determinations and the average. For values of over 5.0 g simply report as + 5.0 g or > 5.0 g.
9.2 Report the test method number and which piece of equipment was used.
10. Precision and Bias
10.1 Precision. In 1998, a limited in- tralaboratory study was completed. The same operator tested all samples.
10.1.2 Three sets of fabrics were analyzed using both pieces of equipment. Each fabric was evaluated 15 times and averages calculated for each group of three. This single laboratory data set was analyzed and used in writing a temporary precision statement, pending a full inter- laboratory study. Until a full study is completed, users of the method are advised to exercise conventional statistical caution in making any comparisons of test results and apply these findings with due caution.
10.1.3 Variances ranged in value from 0.1-0.4 with an average value of 0.23 (standard deviation = 0.48) for the Type I tester, as determined by analysis of variance. Critical differences, based on these values and a 95% probability level, may be applied to determine significance (see Table I).
10.1.4 Variances ranged in value from 0.0-0.1 with an average value of 0.01 (standard deviation = 0.10) for the Type II tester, as determined by analysis of variance. Critical differences, based on these values and a 95% probability level, may be applied to determine significance (see Table II).
10.2 Bias. The values derived by this procedure can be defined only in terms of a test method. There is no independent, referee method for determining the true value. This test method has no known bias. 11. Notes 11.1 Impact Penetration Testers (see Figs. 1, 2, 3 and 4). These testers, Types I and II, are a combination of the spray test apparatus used in AATCC Method 22, plus the impact penetration head and stand. The Type II tester is a more sturdy version of the Type I tester with the addition of a drip catcher. Both these testers are available from AATCC, P.O. Box 12215, Research Triangle Park NC 27709; tel: 919/549-8141; fax: 919/549-8933; e-mail: orders@aatcc.org.
11.2 Blotters suitable for this test can be obtained from AATCC, P.O. Box 12215, Research Triangle Park NC 27709; tel: 919/ 549-8141; fax: 919/549-8933; e-mail: orders@ aatcc.org.AATCC 42 pdf download.