1.1 本试验方法旨在区分固体电绝缘材料对通过含有水分的特定污染物的表面膜传导产生的电弧作用的电阻。试验方法 D2302 ， D2303 ， D3638 和 D5288 也有助于评估材料。 1.2 单位-- 以国际单位制表示的数值为标准。括号中的英寸磅单位仅供参考。每个系统中规定的值不一定是完全相等的；因此，为了确保符合标准，每个系统应独立使用，并且两个系统的值不得组合。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者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: 没有同等的ISO标准。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ===意义和用途====== 6.1 方法-- 如果暴露在高相对湿度和污染环境中，使用中的电气绝缘可能会因跟踪、侵蚀或两者结合而失效。 户外应用中的有机绝缘尤其如此，绝缘表面会被湿气和污垢沉积物污染，例如煤尘或盐雾。该测试方法是一种模拟极端严重室外污染的加速测试。据信，与本试验方法中规定的条件相比，美国户外服务中可能遇到的最严重条件将相对温和。 6.2 测试结果-- 通过这种测试方法，材料可以分为耐跟踪、受跟踪影响或易跟踪。适用于特定用途的这些类别的确切测试值将在适当的材料规范中规定，但在 注4 .耐跟踪材料，除非首先发生侵蚀失效，否则有可能持续数百小时( 注5 )。侵蚀，尽管它可能会横向发展，但通常会导致垂直于试样表面的失效。因此，只比较相同标称厚度的试样，以抵抗跟踪引起的侵蚀。通过测量侵蚀的穿透深度来估计侵蚀的程度。将不易跟踪的材料分为三大类——耐侵蚀、受侵蚀和易受侵蚀。当对标准厚度试样进行测试时，以下失效时间代表了类别( 注释6 ): 易受侵蚀 5. h至50 h 受侵蚀影响 50 h至200 h 耐侵蚀性 超过200小时 注4: 跟踪易感材料通常在5小时内失败。跟踪受影响的材料通常在约100小时前失败。 注5: 该信息来源于自1957年6月作为建议测试方法发布以来，八个实验室使用该测试方法的个人经验，以及这些实验室组织的测试计划的结果。 注6: 在正态分布中，约68 % 所有测试值的平均值均包含在±1标准偏差内。 6.3 测试结果的解释-- 此测试方法提供的信息允许按中所述进行分类 6.2 .除非测试了三个或三个以上的重复样本，否则同一组内材料的比较可能是不明确的。 当测试方法用于规范目的时，不要在没有考虑测试结果中预期的大方差的情况下建立简单的最小值。建议通过统计技术确定质量水平和规格最小值。

1.1 This test method is intended to differentiate solid electrical insulating materials with respect to their resistance to the action of electric arcs produced by conduction through surface films of a specified contaminant containing moisture. Test Methods D2302 , D2303 , D3638 , and D5288 are also useful to evaluate materials. 1.2 Units— The values stated in SI units are the standard. The inch-pound units in parentheses are for information only. 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. 1.3 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 equivalent ISO standard. 1.4 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 ====== 6.1 Method— It is possible that electrical insulation in service will fail as a result of tracking, erosion, or a combination of both, if exposed to high relative humidity and contamination environments. This is particularly true of organic insulations in outdoor applications where the surface of the insulation becomes contaminated by deposits of moisture and dirt, for example, coal dust or salt spray. This test method is an accelerated test that simulates extremely severe outdoor contamination. It is believed that the most severe conditions likely to be encountered in outdoor service in the United States will be relatively mild compared to the conditions specified in this test method. 6.2 Test Results— Materials can be classified by this test method as tracking-resistant, tracking-affected, or tracking-susceptible. The exact test values for these categories as they apply to specific uses will be specified in the appropriate material specifications, but guideline figures are suggested in Note 4 . Tracking-resistant materials, unless erosion failure occurs first, have the potential to last many hundreds of hours ( Note 5 ). Erosion, though it is possible that it will progress laterally, generally results in a failure perpendicular to the specimen surface. Therefore, compare only specimens of the same nominal thickness for resistance to tracking-induced erosion. Estimate the extent of erosion from measurements of the depth of penetration of the erosion. Place materials that are not tracking-susceptible in three broad categories—erosion-resistant, erosion-affected, and erosion-susceptible. When the standard thickness specimen is tested, the following times to failure typify the categories ( Note 6 ): Erosion-susceptible 5 h to 50 h Erosion-affected 50 h to 200 h Erosion-resistant over 200 h Note 4: Tracking-susceptible materials usually fail within 5 h. Tracking-affected materials usually fail before about 100 h. Note 5: This information is derived from the individual experiences of eight laboratories using this test method since its publication as a suggested test method in June 1957, and from the results of an organized test program among these laboratories. Note 6: In a normal distribution approximately 68 % of all test values are included within ±1 standard deviation of the mean. 6.3 Interpretation of Test Results— This test method provides information that allows classification as described in 6.2 . The comparison of materials within the same group is likely to be ambiguous unless three or more replicate specimens are tested. When the test method is used for specification purposes, do not establish simple minimum values without consideration of the large variance to be expected in test results. It is recommended that quality levels and specification minima be determined by statistical techniques.