Several issues that must be paid attention to when adjusting and repairing multimeters

DC current part: The moving coil should be installed correctly, and there should be no ferromagnetic material in the moving gap. If the shunt resistor is burned out, it should be replaced according to the marked value on the circuit diagram. If the meter is highly sensitive, it can be demagnetized, the hairspring can be replaced, or the brake coil can be re-wound. Clean the movable contacts of the transfer switch and re-solder them if they are desoldered or weakly soldered.

DC voltage part: Adjustment of the DC voltage circuit can only be carried out after the current circuit has been adjusted. When adjusting and repairing, proceed step by step from small quantity limit to large quantity limit. The common resistance related to the DC current cannot be adjusted again.

AC voltage part: The adjustment of the AC voltage part mainly focuses on the rectifier components, such as breakdown, damage, and reduction of reverse resistance of the rectifier components. When replacing, choose a tube that is close to its original characteristics. Similarly, anything related to DC current and DC voltage cannot be readjusted.

Resistor part: Replace if the battery is insufficient. If there is any rust on the contact points, clean them. If necessary, lightly sand them with fine sandpaper and add a thin layer of Vaseline. The electromagnetic clamp should be flexible enough. When adjusting, start from R*1 level to the maximum level. Any resistance related to current and voltage loops is not allowed to be adjusted again.