【国外标准】 Standard Test Method for Elongation of Leather

4.1 The elongation measurement may be made at any designated load and is expressed as a percentage of the original distance between the jaws or between bench marks of the unstretched specimen. The speed of the machine is important. Speeds under or more than 10 ± 2 in./min (4.2 ± 0.8 mm/s) will give variables in the results, thus affecting the reproducibility of the method. The direction relative to the backbone and the width of the test specimen determines the magnitude of the elongation. This test method is excellent for development, control, specification acceptance, and service evaluation of leather. This test method may not apply when the conditions of the test employed differ widely from those specified in the test method.1.1 This test method covers the measurement of the elongation or stretch characteristics of leather produced by a tensile load. This test method is intended for use on all types of leather and with all of the breaking load tests. This test method does not apply to wet blue.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 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.1.4 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.