1.1 本规程涵盖了适用于按照规程进行的封闭碳弧装置中塑料暴露的具体程序和试验条件 G151页 和 G153页 . 本规程还包括试样的制备、适用于塑料的试验条件和试验结果的评估。 1.2 本规程不包括塑料的过滤明火碳弧暴露，这在实践中已涵盖 D1499 . 实践 D5031 描述了油漆和相关涂层的封闭碳弧暴露。 1.3 以国际单位制表示的数值应视为标准值。 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。 注1: 没有已知的ISO等效于此做法。 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 塑料材料抵抗因暴露于光、热和水而引起的电气、机械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- 当操作条件在本规程的可接受范围内变化时，可以预期结果的变化； 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 9 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2: 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 封闭碳弧发出的光的光谱功率分布与使用其他碳的光和水暴露装置产生的光谱功率分布有显著不同- 电弧配置或其他光源。暴露于封闭碳弧产生的退化类型和速率以及性能排名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排名大不相同。 4.2.2 只有当所有实验室使用相同类型的碳弧、过滤器和暴露条件时，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排名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；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）。 4. , 5. 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 G153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。

1.1 This practice covers specific procedures and test conditions that are applicable for exposure of plastics in enclosed carbon-arc devices conducted in accordance with Practices G151 and G153 . This practice also covers the preparation of test specimens, the test conditions suited for plastics, and the evaluation of test results. 1.2 This practice does not cover filtered open-flame carbon-arc exposures of plastics, which are covered in Practice D1499 . Practice D5031 describes enclosed carbon-arc exposures of paints and related coatings. 1.3 The values stated in SI units are to be regarded as standard. 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. Note 1: There is no known ISO equivalent to this practice. 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 plastic material to resist deterioration of its electrical, mechanical, 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 Caution— Variation in results can be expected when operating conditions are varied within the accepted limits of this practice; therefore, no reference to the use of this practice shall be made unless accompanied by a report prepared in accordance with Section 9 that describes the specific operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained in accordance with this practice. Note 2: 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 enclosed 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 enclosed carbon arcs can be much different from those produced by exposures to other types of laboratory light sources. 4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same type of carbon arc, filters, 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; therefore, exposure of a similar material of known performance (a control) at the same time as the test materials is strongly recommended. 4 , 5 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 G153 . Significant factors include regulation of line voltage, freedom from salt or other deposits from water, temperature and humidity control, and conditions of the electrodes.