金属氧化物避雷器的非线性电阻阀片主要成分是氧化锌，氧化锌的电阻片具有极为优越的非线性特性。正常工作电压下其电阻值很高，实际上相当于一个绝缘体，而在过电压作用下，电阻片的电阻很小，残压很低。但正常工作电压下，由于阀片长期承受工频电压作用而产生劣化，引起电阻特性的变化，导致流过阀片的泄漏电流的增加。电流中的阻性分量急剧增加，会使阀片上温度上升而发生热崩溃，严重时，甚至引起避雷器的爆炸事故。依照规程1规定，金属氧化物避雷器的检测项目共6项，分别为（1）绝缘电阻（2）直流U1mA及0.75U1mA下的泄漏电流（3）运行电压下的交流泄漏电流（4）工频参考电流下的工频参考电压（5）底座绝缘电阻（6）检查放电计数器动作情况。

The main component of the non-linear resistance valve of the metal oxide arrester is zinc oxide, and the resistance chip of zinc oxide has excellent nonlinear properties. Under normal working voltage, the resistance is very high, which is actually equivalent to an insulator, and under the overvoltage, the resistance is small and the residual pressure is low. But under normal working voltage, because the valve long-term degradation under power frequency voltage function, cause the change of resistance characteristics, lead to the increase of leakage current flow through the valve. A sharp increase in the resistance component of the current can cause heat to rise on the disc and cause heat to collapse, and even cause an explosion in a lightning arrester. In accordance with the provisions of the code 1, detection of metal oxide surge arrester project a total of 6 items, respectively (1) (2) dc U1mA insulation resistance and leakage current under 0.75 U1mA (3) under the operating voltage of ac leakage current (4) refer to the running power frequency electric power frequency reference voltage (5) the base (6) check the insulation resistance discharge counter action.