1、测量避雷器的绝缘电阻：目的在于初步检查避雷器内部是否受潮；有并联电阻者可检查其通、断、接触和老化等情况。
1. Measure the insulation resistance of the arrester: the purpose is to preliminarily check whether the arrester is damped inside; if there is parallel resistance, check its on, off, contact and aging conditions.
2、电导电流和直流1mA下的电压U1mA的测量：试验目的是检查避雷器并联电阻是否受潮、劣化、断裂，以及同相各元件的α系数是否相配；对无串联间隙的金属氧化物避雷器则要求测量直流1mA下的电压及75%该电压下的泄漏电流。
2. Measurement of conductance current and voltage U1mA under DC 1mA: the purpose of the test is to check whether the parallel resistance of the arrester is damped, deteriorated and broken, and whether the α coefficient of each component in the same phase matches; for metal oxide arrester without series gap, it is required to measure the voltage under DC 1mA and the leakage current under 75% of the voltage.
3、测量工频放电电压：是FS避雷器和有串联间隙金属氧化物避雷器的必做项目，其试验的目的，是检查间隙的放电电压是否符合要求。
3. Measurement of power frequency discharge voltage: it is a necessary item for FS arrester and metal oxide arrester with series gap. The purpose of the test is to check whether the discharge voltage of the gap meets the requirements.
4、测量运行电压下的交流泄露电流：试验目的是监测金属氧化物避雷器，判断是否出现故障保障避雷器的安全运行。
4. Measure the AC leakage current under the operating voltage: the purpose of the test is to monitor the metal oxide arrester and judge whether there is a fault to ensure the safe operation of the arrester.
5、测量工频参考电流下的工频参考电压：工频参考电压是无间隙金属氧化物避雷器的一个重要参数，它表明阀片的伏安特性曲线饱和点的位置。运行一定时期后，工频参考电压的变化能直接反映避雷器的老化、变质程度。
5. Measure the power frequency reference voltage under the power frequency reference current: the power frequency reference voltage is an important parameter of gapless metal oxide arrester, which indicates the position of the saturation point of the V-A characteristic curve of the valve piece. After a certain period of operation, the change of power frequency reference voltage can directly reflect the aging and deterioration degree of arrester.
6、检查放电计数器动作情况：目的在于检查放电计数器是否正常工作。
6. Check the action of discharge counter: the purpose is to check whether the discharge counter works normally.