【国外标准】 Standard Test Methods for Measuring Zipper Dimensions

4.1 The significance of specific tests is discussed in the appropriate sections.4.2 These test methods are considered satisfactory for acceptance testing of commercial shipments because the test methods have been used extensively in the trade for this purpose, and because current estimates of between-laboratory precision are acceptable in most cases.4.2.1 In case of a dispute arising from differences in reported test results when using Test Methods D2060 for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If a bias if found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results in the light of the known bias.4.3 The test method(s) in these test methods, along with those in Test Methods D2051, D2052, D2053, D2054, D2057, D2058, D2059, D2061, and D2062, are a collection of proven test methods. They can be used as aids in the evaluation of zippers without the need for a thorough knowledge of zippers. The enumerated test methods do not provide for the evaluation of all zipper properties. Besides those properties measured by means of the enumerated test methods there are other properties that may be important for the satisfactory performance of a zipper. Test methods for measuring those properties have not been published either because no practical methods have yet been developed or because a valid evaluation of the information resulting from existing unpublished methods requires an intimate and thorough knowledge of zippers.1.1 These test methods cover the measurement of the dimensions of all types and sizes of zippers.1.2 The test methods appear as follows:  SectionsChain Flatness 34 – 39Chain Straightness 40 – 44Chain Thickness 28 – 33Chain Width 45 – 50Length of Zipper or Parts  9 – 14Longitudinal Dimensional Change 51 – 58Slider Mouth Width 21 – 27Tape Width 15 – 201.3 The values stated in either SI units or in other units shall be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently of the other, without combining values in any way.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.