1.1 本规程描述了用于选择风化参考材料（WRM）的标准，以及用于确定实验室内和实验室间风化参考材料测量性能变化公差的程序。本规程还描述了比较同一类型风化参考材料不同批次的程序。 注1: 实验室加速试验的例子，其中风化参考材料可用于监测一致性，如实践中所述的暴露试验 G152 , G153 , G154 ，以及 G155 以及引用根据这些标准进行的测试的其他标准。可使用风化参考材料监测一致性的室外暴露示例是根据惯例进行的 G7 , G24 ，或 G90 参考材料也可用于监测不涉及光照的暴露或调节测试的一致性。 1.2 风化参考材料最常用于( 1. )监测暴露试验的一致性（即重复性、再现性或两者兼具）( 2. )为了确定评估测试材料的时间或辐射暴露( 3. )作为与同时暴露的测试材料进行比较的参考材料。风化参考材料不能用于对任何暴露试验的相对严重程度进行分类或表征，因为材料对光、热和水的影响反应存在很大差异。 1.3 本规程不包括控制材料，根据定义，这些控制材料被选择为与试验材料具有相似的成分和结构，并且与试验材料同时暴露。 1.4 本规程概述了确定参考材料的测量性能如何随暴露于指定测试条件而变化所需的实验。它包括建立可重复的测量程序，确定导致变化的光源中的临界光谱区域，以及温度和湿度等其他临界暴露应力的影响。 1.5 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》中确立的国际公认的标准化原则制定的。 =====意义和用途====== 4.1 风化参考物质用于实验室加速暴露试验，以验证在同一仪器内不同时间（重复性）或在不同仪器或不同实验室（再现性）使用相同暴露条件或两者进行的试验的一致性。 注2: SAE J2412和SAE J2527中给出了用于此目的的风化参考材料的示例，用于透明聚苯乙烯材料和AATCC TM16.1- 3或ISO 105-B02适用于蓝色羊毛材料。 4.2 风化参考材料用于自然风化试验，以评估季节/年度变化引起的一致性，或分析特定的暴露变量（如暴露角度、位置、背衬配置等）。 4.3 定义暴露条件一致性的规范基于参考材料在规定时间后的性质变化。一些风化参考材料用于定义暴露时间。 建议使用这些材料的规范要求材料暴露在外，直到风化参考材料发生规定的变化。规格通常基于单批风化参考材料的结果。当引入新批次的参考材料时，有必要进行循环研究，以比较新批次和旧批次，并为新批次的预期性能确定适当的限值。 注3: 一些风化参考材料（例如蓝色羊毛）也用于定义暴露时间。 虽然本标准没有具体涵盖，但用于监测暴露一致性的参考材料表征程序通常也适用于用于定义暴露期的参考材料的表征。 4.4 使用风化参考材料测试实验室加速装置中暴露的一致性非常重要，风化参考材料对测试条件的反应与测试材料的反应方式相似。因此，优选的是，风化参考材料对主要负责在测试材料中产生降解的光源的光谱区域敏感，以提供对暴露测试一致性的最有意义的评估，并提供有关温度和湿度条件一致性的信息，如果后者是测试材料降解的重要因素。 注4: 材料均匀性也是选择风化参考材料的重要因素，特别是如果风化是由杂质吸收的辐射引发的，就像暴露在超过300nm辐射下的脂肪族聚合物一样。 4.5 风化参考材料特性的测量可能会出现误差，具体取决于用于测量特性的仪器和程序。重要的是使用清晰的测量程序，尽量减少操作员误解的机会。 确定特征属性测量引起的可变性水平也很重要。 4.6 当使用参考材料来监测或指定暴露试验的一致性时，重要的是，参考材料变化所定义的任何规格限制都应基于对正确设计的循环实验结果的合理统计分析。本规程提供了一个可遵循的程序，用于建立循环试验、分析结果，并确定可用于规范的参考材料特征特性的合理变化范围。 4.6.1 根据本规程获得的结果仅适用于循环试验中使用的暴露循环，不能应用于不同暴露循环中使用的相同风化参考材料。 4.7 参考材料的特性变化可能受到曝光装置中参考材料放置的影响。这通常是由于在允许的暴露区域内光强度和温度的变化。在整个允许的暴露区域内随机放置风化参考材料的复制试样，可以表明暴露区域内条件的均匀性。 注5: 在某些情况下，程序要求在暴露装置或室内的特定位置暴露风化参考材料。以这种方式使用的参考材料的结果可能无法准确表示设备内其他位置的暴露条件。

1.1 This practice describes the criteria to be used for selection of a weathering reference material (WRM) and procedures to be used for determining within lab and between lab tolerances of changes in measured properties of weathering reference materials. This practice also describes a procedure for comparing different lots of the same type of a weathering reference material. Note 1: Examples of laboratory accelerated tests in which a weathering reference material could be used to monitor consistency are exposure tests such as those described in Practices G152 , G153 , G154 , and G155 and other standards in which tests conducted according to these standards are referenced. Examples of outdoor exposures where a weathering reference material could be used to monitor consistency are those conducted according to Practices G7 , G24 , or G90 . A reference material can also be used to monitor consistency of exposure or conditioning test that do not involve exposure to light. 1.2 Weathering reference materials are most often used to ( 1 ) monitor consistency (that is, repeatability, reproducibility, or both) of exposure tests, ( 2 ) to determine the time or radiant exposure at which test materials are evaluated, ( 3 ) as a reference material for comparing to test materials exposed at the same time. Weathering reference materials cannot be used to classify or characterize the relative severity of any exposure test because of the large variability in material responses to the effects of light, heat, and water. 1.3 This practice does not cover control materials which, by definition are selected to be of similar composition and construction to the test materials, and are exposed at the same time as test materials. 1.4 This practice provides an outline of experiments required to determine how the measured properties of the reference material change as a function of exposure to specified test conditions. It includes establishment of reproducible measurement procedures, determination of the critical spectral region in the light source causing the changes, and effects of other critical exposure stresses such as temperature and moisture. 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. ====== Significance And Use ====== 4.1 Weathering reference materials are used in laboratory accelerated exposure tests to verify consistency of tests run within the same instrument at different times (repeatability) or in different instruments or different laboratories (reproducibility), using the same exposure conditions, or both. Note 2: Examples of weathering reference materials used for this purpose are given in SAE J2412 and SAE J2527 for clear polystyrene material and AATCC TM16.1-3 or ISO 105-B02 for blue wool material. 4.2 Weathering reference materials are used in natural weathering tests to evaluate consistency due to seasonal/annual variation or to analyze specific exposure variables (such as exposure angle, location, backing configuration, etc.). 4.3 Specifications defining consistency of exposure conditions are based on the property change of a reference material after a defined period of time. Some weathering reference materials are used to define periods of exposure. Specifications recommending the use of these materials require the material to be exposed until a defined change in the weathering reference material is achieved. Specifications are usually based on results for a single lot of the weathering reference material. When a new lot of the reference material is introduced, round-robin studies are necessary to compare the new and old lots and to establish appropriate limits for expected performance of the new lot. Note 3: Some weathering reference materials (for example blue wools) are also used to define periods of exposure. Although not specifically covered by this standard, the procedures described for characterizing a reference material used to monitor consistency of exposures are also generally applicable to characterizing reference materials used to define periods of exposure. 4.4 It is important to test the consistency of exposure in the laboratory accelerated device with a weathering reference material that responds to the test conditions similar to the way the test materials respond. Therefore, it is preferable that the weathering reference material be sensitive to the spectral region of the light source mainly responsible for producing degradation in the test materials to provide the most meaningful evaluation of exposure test consistency, as well as providing information on consistency of temperature and humidity conditions if the latter are important factors in degradation of the test materials. Note 4: Material homogeneity can also be an important factor in selection of a weathering reference material, particularly if weathering is initiated by the radiation absorbed by impurities as is the case in aliphatic type polymers exposed to radiation longer than 300 nm. 4.5 The measurement of the characteristic property of a weathering reference material can be subject to error depending on the instrument and the procedure used to measure the property. It is important to use measurement procedures that are clear and which minimize chances for operator misinterpretation. It is also important to determine the level of variability caused by measurement of the characteristic property. 4.6 When a reference material is used to monitor or specify the consistency of an exposure test, it is important that any specification limits defined by changes in the reference material be based on a sound statistical analysis of results from a properly designed round-robin experiment. This practice provides a procedure which can be followed to set up the round-robin, analyze results, and establish reasonable limits of change in the characteristic property of the reference material that can be used in specifications. 4.6.1 The results obtained according to this practice are valid only for the exposure cycle used for the round-robin and cannot be applied to the same weathering reference material used in different exposure cycles. 4.7 The change in characteristic property of a reference material may be affected by the placement of the reference material in the exposure device. This is often due to variations in light intensity and temperature within the allowed exposure area. Random placement of replicate specimens of the weathering reference material throughout the allowed exposure area provides an indication of the uniformity of conditions within the exposure area. Note 5: In some cases, procedures require exposure of a weathering reference material at a specific location within the exposure device or chamber. Results for a reference material used in this way may not provide an accurate representation of the exposure conditions in other positions within the device.