1.1本规程涵盖了使用封闭式碳弧灯和水设备的基本原理和操作程序，该设备旨在再现材料在实际使用中暴露于阳光（直接或通过窗户玻璃）和雨水或露水等水分时发生的风化效应。本规程仅限于获取、测量和控制暴露条件的程序。附录中列出了许多暴露程序；然而，本规程并未规定最适合待测材料的暴露条件。 注1 — 实践 G151页 描述了使用实验室光源的所有曝光设备的性能标准。 本练习取代练习 G23集团 ，它描述了用于碳弧曝光的设备的非常具体的设计。实践中描述的装置 G23集团 包含在本实践中。 1.2在受控环境条件下，将试样暴露在封闭的碳弧光下。 1.3特定材料的各种方法或规范涵盖了样本制备和结果评估。在实践中给出了一般指导 G151页 和ISO 4892-1 . ISO 4582中描述了有关确定暴露后性能变化和报告这些结果的方法的更具体信息 . 1.4以国际单位制表示的数值应视为标准。 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和健康实践，并确定监管限制的适用性。 1.5.1如果光源操作产生任何臭氧，应通过排气系统将其从试样和操作人员身上带走。 ====意义和用途====== 5.1本仪器的使用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。这些暴露可能包括将水分引入试样的方法。 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。或者，曝光可以模拟阳光透过窗户玻璃的效果。通常，这些暴露包括以湿度形式存在的水分。 注释2 — 注意事项: 参考实践 G151页 适用于所有实验室风化设备的完整警示指南。 5.2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，除非随附一份报告，详细说明符合第节规定的具体操作条件，否则不得参考使用本规程的结果 10 . 5.2.1建议与试样同时暴露具有已知性能的类似材料（对照），以提供用于比较目的的标准。最佳做法是使用已知耐久性相对较差且良好的控制材料。建议在每次试验中至少对每种评估材料进行三次重复试验，以便对结果进行统计评估。

1.1 This practice covers the basic principles and operating procedures for using enclosed carbon-arc light and water apparatus intended to reproduce the weathering effects that occur when materials are exposed to sunlight (either direct or through window glass) and moisture as rain or dew in actual use. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure. A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested. Note 1 — Practice G151 describes performance criteria for all exposure devices that use laboratory light sources. This practice replaces Practice G23 , which describes very specific designs for devices used for carbon-arc exposures. The apparatus described in Practice G23 is covered by this practice. 1.2 Test specimens are exposed to enclosed carbon arc light under controlled environmental conditions. 1.3 Specimen preparation and evaluation of the results are covered in various methods or specifications for specific materials. General guidance is given in Practice G151 and ISO 4892-1 . More specific information about methods for determining the change in properties after exposure and reporting these results is described in ISO 4582 . 1.4 The values stated in SI units are to be regarded as the standard. 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 and health practices and determine the applicability of regulatory limitations prior to use. 1.5.1 Should any ozone be generated from the operation of the light source, it shall be carried away from the test specimens and operating personnel by an exhaust system. ====== Significance And Use ====== 5.1 The use of this apparatus is intended to induce property changes associated with the end use conditions, including the effects of sunlight, moisture, and heat. These exposures may include a means to introduce moisture to the test specimen. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure. Alternatively, the exposure may simulate the effects of sunlight through window glass. Typically, these exposures would include moisture in the form of humidity. Note 2 — Caution: Refer to Practice G151 for full cautionary guidance applicable to all laboratory weathering devices. 5.2 Variation in results may be expected when operating conditions are varied within the accepted limits of this practice. Therefore, no reference shall be made to results from the use of this practice unless accompanied by a report detailing the specific operating conditions in conformance with Section 10 . 5.2.1 It is recommended that a similar material of known performance, a control, be exposed simultaneously with the test specimen to provide a standard for comparative purposes. It is best practice to use control materials known to have relatively poor and good durability. It is recommended that at least three replicates of each material evaluated be exposed in each test to allow for statistical evaluation of results.