1.1 本指南涵盖了关于可变性来源和减少暴露试验的策略的信息，以及在外部和实验室加速暴露试验的设计、执行和数据分析中考虑可变性的信息。 1.2 以国际单位制表示的数值应单独视为标准。括号中给出的英寸-磅值仅供参考。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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====== 4.1 许多标准和规范参考了根据非金属材料耐久性委员会G03负责的标准进行的暴露试验。在许多情况下，使用这些测试中生成的数据未能考虑暴露测试实践中可变性的影响。这种可变性可能会对暴露试验结果的解释产生深远影响，如果在试验设计和数据分析中不加以考虑，可能会导致错误或误导性结论。本指南列出了测试可变性的一些来源，并推荐了成功进行风化研究的策略。本指南中并未提及风化试验中的所有可变性来源。特定材料、取样程序、试样制备、试样调节和材料性能测量可能会显著影响风化试验结果的可变性。 指南中解决了其中许多问题 G147页 . 为了减少仪器方法对测试可变性的贡献，必须遵循与特定特性测量相关的适当校准程序和ASTM标准。指南中列出了测试结果可变性的其他来源 D4853 ，以及确定可能原因的方法。

1.1 This guide covers information on sources of variability and strategies for its reduction in exposure testing, and for taking variability into consideration in the design, execution, and data analysis of both exterior and laboratory accelerated exposure tests. 1.2 The values stated in SI units are to be regarded separately as the standard. The inch-pound values given in parentheses are for information only. 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. ====== Significance And Use ====== 4.1 Many standards and specifications reference exposure tests performed according to standards that are the responsibility of Committee G03 on Durability of Nonmetallic Materials. In many cases, use of the data generated in these tests fails to consider the ramifications of variability in the exposure test practices. This variability can have a profound effect on the interpretation of results from the exposure tests, and if not taken into consideration in test design and data analysis, can lead to erroneous or misleading conclusions. This guide lists some of the sources for test variability and recommends strategies for executing successful weathering studies. Not all sources of variability in weathering testing are addressed in this guide. Specific materials, sampling procedures, specimen preparation, specimen conditioning, and material property measurements can contribute significantly to variability in weathering test results. Many of these concerns are addressed in Guide G147 . To reduce the contribution of an instrumental method to test variability, it is essential to follow appropriate calibration procedures and ASTM standards associated with the particular property measurement. Additional sources of variability in test results are listed in Guide D4853 , along with methods for identifying probable causes.