GB/T 21222-2007 in English

《GB/T 21222-2007绝缘液体 雷电冲击击穿电压测定方法》由TC51（全国绝缘材料标准化技术委员会）归口，主管部门为中国电器工业协会。
本标准规定了两种试验方法A和B，用来评定绝缘液体在发散场下经受标准雷电脉冲的电气强度。方法A用来评定在规定条件下的脉冲击穿电压。方法B用来检验绝缘液体在给定的电压等级下脉冲击穿概率的假设。

Scope

1.1 This standard specifies two test methods A and B, which are used to evaluate the electric strength of insulating liquids subjected to standard lightning pulses in a divergent field. Method A is based on a step-by-step test procedure for evaluating the pulse breakdown voltage under specified conditions. Method B is a statistical test to test assumptions about the probability of pulse breakdown of insulating liquids at a given voltage level. 1.2 Both methods are applicable to unused or used insulating liquid, the viscosity of which should be lower than 700mm²/s at 40℃. Both methods can use positive and negative pulses. There are no special regulations regarding the preparation of liquid samples as long as they meet the requirements for industrial use. However, tests performed on samples before and after treatment can show how effective the treatment is. 1.3 Two methods are mainly used to establish standard procedures for evaluating the impulse electric strength of insulating liquids. These procedures are used to distinguish between different dielectric liquids, and can also be used to detect changes in the chemical composition of the liquid when the manufacturing process or raw material changes, and the resulting change in properties.