First, with a multimeter to measure the leakage voltage, the multimeter switch on the AC voltage measurement file, generally placed on the AC voltage 250V gear, and then insert the black pen into the soil near the measured equipment, the red pen is connected to the metal casing of the equipment. At this time to see the multimeter on the number of instructions, if the needle does not move, can be changed in turn to put the low gear, until the indication of the specific data that is the leakage voltage of the equipment. If when the pen in the lowest gear is still no indication, that is, the equipment does not leakage phenomenon exists.