1.1 本规程涵盖三种类型的实验室风化暴露程序，用于评估光化辐射、热量和水分对密封剂的影响。 1.2 根据实践，三种人工风化装置中使用的暴露源是过滤氙弧、荧光紫外线灯和明火碳弧 G155页 , G154页 和 G152页 分别地 1.3 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.4 与本规程相关的ISO标准为ISO 11431。程序之间存在显著差异。ISO试样通过玻璃暴露，并在暴露后检查附着力或内聚力或两者的损失之前拉长。 1.5 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。 1.6 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====== 5.1 本规程确定了在受控实验室人工气候试验条件下，光化辐射、高温和水分对密封剂及其成分的影响。 5.2 在使用实验室光源的设备中进行曝光时，重要的是要考虑 (1) 人工测试条件将在多大程度上再现被测试密封剂的最终使用环境引起的性能变化和故障模式，以及 (2) 密封剂的稳定性排名。参考实践 G151页 有关实验室风化的完整警示指南。 5.3 由于暴露源（氙弧、荧光紫外线灯和明火碳弧）的光谱功率分布不同，以及三种实验室风化试验中使用的其他条件，包括温度、水分类型和数量以及试验周期，这三种程序可能不会导致密封剂的相同性能等级或失效模式类型。 此外，通过三种暴露类型测试密封剂的耐候性能可能需要不同的暴露时间。不应比较暴露在不同类型仪器中的密封剂的相对稳定性。 5.4 当操作条件在本规程的可接受范围内变化时，结果可能会发生变化。因此，使用本规程的所有测试结果必须随附第节要求的特定操作条件报告 10 . 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。 5.5 实验室暴露试验不能指定为室外环境中实际使用条件的完全模拟。由于紫外线辐射、湿润时间、相对湿度、温度、污染物和其他因素的差异，材料在实际使用条件下的相对耐久性在不同位置可能会有所不同。只有在为所测试的特定材料建立秩相关度且失效模式相同时，从这些实验室加速暴露中获得的结果才能被视为实际使用暴露的代表。 暴露具有已知室外性能的类似材料（对照品）以及试样，可以在测试条件下进行相对耐久性评估，这也大大提高了不同实验室之间测试结果的一致性。 5.6 实验室加速试验中的暴露时间与产生等效降解所需的室外暴露时间相关的加速系数取决于材料，对于每种材料和同一材料的不同配方，加速系数可能会显著不同。 因此，不能假设为一种材料确定的加速度系数适用于其他材料。 5.7 该程序的结果将取决于根据实践操作设备时的谨慎程度 G152页 , G154页 和 G155页 . 重要因素包括线路电压的调节、不含盐或其他水沉积物、温度控制、湿度控制（如适用）、氙弧设备中燃烧器和过滤器的条件和使用寿命，以及荧光紫外线设备中灯具的使用寿命。 注1: 指南中提供了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 G141页 .

1.1 This practice covers three types of laboratory weathering exposure procedures for evaluating the effect of actinic radiation, heat, and moisture on sealants. 1.2 The exposure sources used in the three types of artificial weathering devices are the filtered xenon arc, fluorescent ultraviolet lamps, and open flame carbon arc based on Practices G155 , G154 , and G152 , respectively. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.4 The ISO standard related to this Practice is ISO 11431. Significant differences exist between the procedures. The ISO specimens are exposed through glass and are elongated prior to examination for loss of adhesion or cohesion, or both, following exposure. 1.5 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. 1.6 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 This practice determines the effects of actinic radiation, elevated temperature, and moisture on sealants and their constituents under controlled laboratory artificial weather test conditions. 5.2 When conducting exposures in devices which use laboratory light sources, it is important to consider (1) how well the artificial test conditions will reproduce property changes and failure modes caused by end-use environments on the sealant being tested and (2) the stability ranking of sealants. Refer to Practice G151 for full cautionary guidance regarding laboratory weathering. 5.3 Because of differences in the spectral power distributions of the exposure sources (xenon arc, fluorescent UV lamps, and open flame carbon arc), as well as other conditions used in the three types of laboratory weathering tests, including temperature, type and amount of moisture, and test cycles, these three procedures may not result in the same performance ranking or types of failure modes of sealants. Further, different exposure durations may be required for testing the weathering performance of sealants by the three types of exposures. Comparisons should not be made of the relative stability of sealants exposed in the different types of apparatus. 5.4 Variations in results may be expected when operating conditions are varied within the accepted limits of this practice. Therefore, all test results using this practice must be accompanied by a report of the specific operating conditions as required in Section 10 . Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained according to this practice. 5.5 No laboratory exposure test can be specified as a total simulation of actual use conditions in outdoor environments. The relative durability of materials in actual use conditions can vary in different locations because of differences in UV radiation, time of wetness, relative humidity, temperature, pollutants, and other factors. Results obtained from these laboratory accelerated exposures can be considered as representative of actual use exposures only when the degree of rank correlation has been established for the specific materials being tested and when the failure mode is the same. Exposure of a similar material of known outdoor performance, a control, along with the test specimens provides for evaluation in terms of relative durability under the test conditions, which also greatly improves the agreement in test results among different laboratories. 5.6 The acceleration factor relating the exposure time in a laboratory accelerated test to exposure time outdoors required to produce equivalent degradation is material dependent and can be significantly different for each material and for different formulations of the same material. Therefore, the acceleration factor determined for one material cannot be assumed to be applicable to other materials. 5.7 Results of this procedure will depend on the care that is taken to operate the equipment according to Practices G152 , G154 , and G155 . Significant factors include regulation of the line voltage, freedom from salt or other deposits from water, temperature control, humidity control, where applicable, condition and age of the burners and filters in xenon arc equipment, and age of lamps in fluorescent UV equipment. 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 .