1.1 本规程规定了受控辐照度氙弧灯和水设备的操作程序。该程序使用一个或多个灯具和滤光器在紫外线和可见光范围内产生类似于阳光的辐照度。它还模拟了汽车外部涂层在自然风化条件下经历的吸水和应力循环。这种做法也适用于其他运输车辆的涂层，如飞机、卡车和轨道车。 1.2 本规程使用带有指定滤光片的氙弧光源。灯具和专用日光滤光片的光谱功率分布（SPD）如中所述 附件A1 . 本实践中使用的辐照度水平在0.40和0.80 W/（m）之间变化 2. ·340 nm时。在几个黑暗步骤的部分过程中，将水喷洒在试样上。水的应用使涂层在测试期间能够吸收和解吸大量的水。此外，湿/干和温/冷之间的循环将导致材料产生机械应力。这些测试条件旨在模拟亚热带气候环境（如佛罗里达州南部）的物理和化学应力。 1.3 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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和健康实践，并确定监管限制的适用性。 ====意义和用途====== 5.1 该测试程序用于模拟外部运输应用（例如，汽车）涂层在亚热带气候（如佛罗里达州南部）下暴露的物理和环境应力。已经发现，这种亚热带气候导致此类涂层特别严重的劣化。除了高剂量的太阳辐射外，佛罗里达州南部的长期水暴露和干湿循环对这种恶化尤为重要 ( 3. ) . 本规程旨在解决运输涂料，尤其是汽车涂料历史试验的不足 ( 4. ) . 注1: 该测试程序是通过汽车和航空航天OEM、材料供应商和测试设备制造商之间八年的合作测试开发的。有关这项研究的已发表论文，请参阅参考文献。

1.1 This practice specifies the operating procedures for a controlled irradiance xenon arc light and water apparatus. The procedure uses one or more lamp(s) and optical filter(s) to produce irradiance similar to sunlight in the UV and visible range. It also simulates the water absorption and stress cycles experienced by automotive exterior coatings under natural weathering conditions. This practice has also been found applicable to coatings on other transportation vehicles, such as aircraft, trucks and rail cars. 1.2 This practice uses a xenon arc light source with specified optical filter(s). The spectral power distribution (SPD) for the lamp and special daylight filter(s) is as specified in Annex A1 . The irradiance level used in this practice varies between 0.40 and 0.80 W/(m 2 ·nm) at 340 nm. Water is sprayed on the specimens during portions of several dark steps. The application of water is such that the coatings will absorb and desorb substantial amounts of water during testing. In addition, the cycling between wet/dry and warm/cool will induce mechanical stresses into the materials. These test conditions are designed to simulate the physical and chemical stresses from environments in a subtropical climate, such as southern Florida. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== 5.1 This test procedure is used to simulate the physical and environmental stresses that a coating for exterior transportation applications (for example, automotive) is exposed to in a subtropical climate, such as southern Florida. It has been found that such a subtropical climate causes particularly severe deterioration of such coatings. The long water exposures and wet/dry cycling found in southern Florida are particularly important for this deterioration, in addition to the high dosage of solar radiation ( 3 ) . This practice was developed to address the deficiencies of historical tests used for transportation coatings, especially automotive coatings ( 4 ) . Note 1: This test procedure was developed through eight years of cooperative testing between automotive and aerospace OEM’s, material suppliers, and test equipment manufacturers. See References for published papers on this research.