ASTM D76/D76M-21 PDF

ABSTRACT This specification covers operating characteristics of tensile testing machines for the determination of the force-elongation properties of textile materials. Types of tensile machine covered in this specification are constant-rate-of-extension, constant-rate-of-traverse, and constant-rate-of-loading. Testing machines calibration shall be verified using the methods indicated in this specification, especially when moved to different locations to make sure that they still meet the specified tolerances. Motor-driven machine is preferred over manually driven machine. Constant-rate-of-traverse type machines shall not be used for measuring forces below fifty times their resolution. Machines shall be equipped with a device for measuring force. Clamping or holding devices shall be prescribed in test methods. Maximum allowable error, indicated force, recorded elongation, nominal gage length, and moving clamp speed shall be within the tolerances prescribed in the individual standards. Verification methods for recorded clamp displacement, recorded elongation, and nominal gage length, shall conform to the procedures indicated in this specification. SCOPE 1.1 This specification covers the operating characteristics of three types of tensile testing machines used for the determination of the force-elongation properties of textile materials. These types of tensile testing machines are: 1.1.1 Constant-rate-of-extension, CRE. 1.1.2 Constant-rate-of-traverse, CRT. 1.1.3 Constant-rate-of-loading (force), CRL. 1.2 Specifications for tensile testing machines to measure other tensile-related properties of textile materials not covered by this standard are given in the ASTM standards using those machines. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.4 The following safety hazards caveat pertains only to the test methods described in this specification: 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.