1.1 本规程涵盖了将新的、先前未上漆的木材和木材复合材料上的房屋和装饰油漆直接暴露于环境中所需遵循的程序。当风化试验的发起人由单独机构进行实际暴露时，应明确定义试验和对照样品暴露的具体条件，并由各方共同商定。 1.2 本标准涵盖了试样制备，包括在木材基材上涂覆试验涂料。 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 本规程中描述的程序旨在帮助评估新的、先前未上漆的木材的房屋和装饰涂料的性能。 4.2 由于太阳辐射、湿润时间、温度、污染物和其他因素的差异，油漆在室外暴露中的相对耐久性可能因暴露位置而异。 因此，不能假设单个位置的一次暴露结果将有助于确定不同位置的相对耐久性。建议在不同气候的多个位置进行暴露，这代表了广泛的预期使用条件。 4.2.1 由于年复一年的气候变化，单次暴露试验的结果不能用于预测材料降解的绝对速率。需要几年的重复暴露才能获得给定位置的“平均”测试结果。 4.2.2 太阳辐射随时间变化很大。这可能导致许多油漆的表观降解速率存在很大差异。除非材料同时暴露在同一位置，否则不建议比较短期（少于一年）暴露材料的结果。 4.2.3 建议对每种材料至少进行三次重复试验。 根据已知的材料参数，可以在实践中找到所需重复次数的统计估计 E122 . 4.3 实践中的意义和使用部分 G7集团 解决了外部暴露测试中需要考虑的许多变量。

1.1 This practice covers procedures to be followed for direct exposure of house and trim paints on new, previously unpainted wood and wood composite materials to the environment. When originators of a weathering test have the actual exposure conducted by a separate agency, the specific conditions for the exposure of test and control specimens should be clearly defined and mutually agreed upon between all parties. 1.2 This standard covers specimen preparation including the application of the test paint to the wood substrate. 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 procedure described in this practice is intended to aid in evaluating the performance of house and trim paints to new, previously unpainted wood. 4.2 The relative durability of paints in outdoor exposures can be very different depending on the location of the exposure because of differences in solar radiation, time of wetness, temperature, pollutants, and other factors. Therefore, it cannot be assumed that results from one exposure in a single location will be useful for determining relative durability in a different location. Exposures in several locations with different climates which represent a broad range of anticipated service conditions are recommended. 4.2.1 Because of year-to-year climatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a material degrades. Several years of repeat exposures are needed to get an “average” test result for a given location. 4.2.2 Solar radiation varies considerably as function of time of year. This can cause large differences in the apparent rate of degradation in many paints. Comparing results for materials exposed for short periods (less than one year) is not recommended unless materials are exposed at the same time in the same location. 4.2.3 It is recommended that at least three replicates of each material be tested. A statistical estimate of the number of replicates needed based on parameters known about the material can be found in Practice E122 . 4.3 The Significance and Use section in Practice G7 addresses many variables to be considered in exterior exposure tests.