Troubleshooting of Voltmeter

　　(2) If the voltmeter pointer cannot swing and the meter head is normal, if it is caused by an open circuit in the voltage divider resistor or the temperature compensation resistor, or a broken circuit in the connecting wire, replace the resistor or re-weld the open circuit point (if the compensation resistor is wire-wound, it can be welded, and the insulation treatment must be done after welding the compensation resistor).

　　(3) The zero point is normal, but the range is inaccurate. Check the resistance of the voltage divider resistor. If the resistance has changed, replace it or connect a resistor in series (or in parallel) to achieve the original resistance of the voltage divider resistor (adjustable resistor can be used).

　　(4) The meter works normally in a low temperature environment or at the beginning of use, but after a certain period of use, it begins to malfunction (especially in the hot summer, the measurement errors are large at noon and in the morning and evening). This kind of malfunction is mostly caused by insufficient power of a certain resistor. For maintenance methods, please refer to the ammeter maintenance section.

　　(5) As the usage time increases, the measurement error gradually increases. For the cause and repair method of this fault, please refer to the ammeter maintenance section.