1.1 本规程涵盖了在受控运行和环境条件下进行轮胎耐久性和耐久性试验的1.707-m[67.23-in.]直径实验室车轮的要求。 1.2 以国际单位制或英磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不完全相等；因此，每个系统应独立使用。组合两个系统的值可能导致不符合标准。 1.3 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体的预防说明，请参见第节 7. 和 注1 . 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 1.707米[67.23英寸]直径的实验室试验车轮是轮胎耐久性和耐久性试验中使用最广泛的试验设备之一。 5.2 该试验装置在实验室以受控的表面速度、负载和环境温度运行，在一定程度上模拟轮胎- 类似实际使用的操作条件。由于车轮的曲率，测试轮胎比在道路上行驶的轮胎疲劳得更快。 5.3 本实践中描述的实验室车轮适用于在受控操作和环境条件下对轮胎进行比较评估。 5.4 虽然实验室车轮可能无法准确再现使用中发生的结构疲劳，但实验室车轮可用于在受控条件下产生疲劳。

1.1 This practice covers the requirements for a 1.707-m [67.23-in.] diameter laboratory roadwheel for durability and endurance testing of tires under controlled operating and environmental conditions. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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. For specific precautionary statements, see Section 7 and Note 1 . 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. ====== Significance And Use ====== 5.1 The 1.707-m [67.23-in.] diameter laboratory test roadwheel is one of the most extensively employed testing devices for tire durability and endurance testing. 5.2 This test apparatus operating in the laboratory at controlled surface speeds, loads, and ambient temperatures simulates, to a degree, tire-operating conditions resembling actual service. Because of the roadwheel curvature, the test tire is fatigued more rapidly than a tire operating on a road. 5.3 The laboratory roadwheel described in this practice is suitable for comparative evaluation of tires under controlled operating and environmental conditions. 5.4 While the laboratory roadwheel may not reproduce structural fatigue exactly as it occurs in service, the laboratory wheel can be used to produce fatigue under controlled conditions.