1.1 本规程涵盖了根据规程进行的未过滤明火碳弧装置中涂层和相关产品加速暴露试验的试验条件选择 G151页 和 G152页 . 本规程还包括试样的制备、适用于涂层的试验条件以及试验结果的评估。 1.2 本规程涵盖了油漆和相关涂层的未过滤明火碳弧暴露，并涵盖了通常被称为“露水循环”的暴露周期实践 D822/D822M 介绍了过滤明火碳弧装置和实践 D5031/D5031M 描述封闭的碳弧暴露。未经过滤的明火碳弧产生的辐射比经过滤的明火碳弧产生的波长更短，短波辐射水平更高- 火焰或封闭的碳弧。 1.3 以国际单位制或英寸-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不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.4 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。 1.5 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 涂料或涂层抵抗因暴露于光、热和水而引起的物理和光学性能劣化的能力在许多应用中都非常重要。本规程旨在引起与最终使用条件相关的性能变化，包括阳光、水分和热量的影响。本实践中使用的暴露不是为了模拟局部天气现象引起的恶化，例如大气污染、生物攻击和盐水暴露。 4.2 注意事项- 当使用不同的操作条件时，结果可能会发生变化。因此，除非附有根据第节编制的报告，否则不得提及本惯例的使用 10 这描述了使用的特定操作条件。 参考实践 G151页 有关适用于使用根据本规程获得的结果的注意事项的详细信息。 注1: 关于可变性来源以及解决实验室加速暴露试验设计、执行和数据分析中可变性的策略的更多信息，请参见指南 G141页 . 4.2.1 未经过滤的明火碳弧发出的光的光谱功率分布与使用其他碳弧配置或其他光源的光和水暴露设备中产生的光谱功率分布显著不同。暴露于未经过滤的明火碳弧产生的退化类型和速率以及性能等级可能与暴露于其他类型的实验室光源产生的退化类型和速率以及性能等级有很大不同。通常，根据本规程进行的暴露会比根据规程进行的类似暴露产生更快的降解 D822/D822M 或 D5031/D5031M 并可能导致不同类型的退化。 4.2.2 只有当所有实验室使用相同类型的碳弧和暴露条件时，实验室间比较才有效。 4.3 当根据与其他材料或对照物相比的性能等级来评估材料的稳定性时，实验室之间测试结果的再现性已被证明是良好的。 4. , 5. 因此，强烈建议在试验材料的同时暴露具有已知性能的类似材料（对照）。建议每种材料至少暴露三次，以便对结果进行统计评估。 4.4 测试结果将取决于按照惯例操作设备时的谨慎程度 G152页 . 重要因素包括调节线路电压、不含盐或其他水沉积物、温度和湿度控制以及电极条件。 4.5 根据本规程对暴露的所有参考必须包括对所用试验循环的完整描述。

1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in unfiltered open-flame carbon-arc devices conducted according to Practice G151 and G152 . This practice also covers the preparation of test specimens, the test conditions suited for coatings, and the evaluation of test results. 1.2 This practice covers unfiltered open-flame carbon-arc exposures of paints and related coatings, and covers the exposure cycle that has been commonly referred to as the “dew cycle.” Practice D822/D822M describes filtered open-flame carbon-arc devices, and Practice D5031/D5031M describes enclosed carbon-arc exposures. The radiation from an unfiltered open-flame carbon arc produces shorter wavelengths and higher levels of short wavelength radiation than either filtered open-flame or enclosed carbon arcs. 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 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. ====== Significance And Use ====== 4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat, and water can be very significant for many applications. This practice is intended to induce property changes associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and saltwater exposure. 4.2 Cautions— Variation in results may be expected when different operating conditions are used. Therefore, no reference to the use of this practice shall be made unless accompanied by a report prepared according to Section 10 that describes the specific operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained according to this practice. Note 1: Additional information on sources of variability and on strategies for addressing variability in the design, execution, and data analysis of laboratory accelerated exposure tests is found in Guide G141 . 4.2.1 The spectral power distribution of light from an unfiltered open-flame carbon arc is significantly different from that produced in light and water exposure devices using other carbon-arc configurations or other light sources. The type and rate of degradation and the performance rankings produced by exposures to unfiltered open-flame carbon-arcs can be much different from that produced by exposures to other types of laboratory light sources. Typically, exposures conducted according to this practice will produce degradation faster than similar exposures conducted in accordance with Practice D822/D822M or D5031/D5031M and may cause different types of degradation. 4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon-arc and exposure conditions. 4.3 Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated in terms of performance ranking compared to other materials or to a control. 4 , 5 Therefore, exposure of a similar material of known performance (a control) at the same time as the test materials is strongly recommended. It is recommended that at least three replicates of each material be exposed to allow for statistical evaluation of results. 4.4 Test results will depend upon the care that is taken to operate the equipment in accordance with Practice G152 . Significant factors include regulation of line voltage, freedom from salt or other deposits from water, temperature and humidity control, and conditions of the electrodes. 4.5 All references to exposures in accordance with this practice must include a complete description of the test cycle used.