环境条件分类.第2-2部分:自然界出现的环境条件.降水和风

[中文适用范围]： IEC 60721 的本文部分介绍了与降水和风相关的电气产品环境条件的基本特性、表征量度及分类。本文旨在作为背景材料，用于选择与产品应用相关的降水和风参数的适当严重程度。在选择与产品应用相关的降水和风参数的严重程度时，应应用 IEC 60721-1 中给出的值。 [外文原描述]： IEC 60721-2-2:2012 presents fundamental properties, quantities for characterization, and a classification of environmental conditions dependent on precipitation and wind relevant for electrotechnical products. This second edition cancels and replaces the first edition, published in 1988, and constitutes a technical revision. The main changes with regard to the previous edition are as follows: - subclause Precipitation: simplified; - data not possible to validate are removed; - subclause Wind: text rewritten; - Table 1 simplified and aligned with definition used by [1]; - subclause Hail: data added; - formula changed; - formula for impact energy added; - subclause Snow: text changed and aligned with definitions used by [1]; - Table 3 removed; - subclause Normal rain: text has been modified and numeric values removed; - subclause Driving rain: text has been modified and numeric values removed; - subclause Formation of ice: text has been modified and numeric values removed; - subclause Drifting snow: text added; - subclause Wind force: formula changed; - Figure 1 to 5 removed.