Meter detection methods The following methods, in normal circumstances, indicate that the isolation is working properly, and vice versa, that the meter works badly. Step 1: In case of wireless connection, you can shake the handle in the direction of the needles of a watch. Step 2: in normal conditions, hand slip ∞. Step 3: Black test pen connected to the E., Red pen connected to the end L, test clip for the buttock test. Step 4: Slowly turn the handle in the opposite direction of the needles of a watch, the pointer returns to zero.