Multimeter adjustment and parts replacement method
About the adjustment and parts replacement method of the multimeter, the daily adjustment and maintenance of the multimeter, including the adjustment method of the DC current part, the DC voltage part, the AC voltage part and the resistance part of the multimeter.
Multimeter Repair and Parts Replacement
1. DC current part
The moving coil should be installed correctly, and there should be no ferromagnetic substances in the movable gap. If the shunt resistor is burned out, it should be replaced according to the marked value on the circuit diagram.
If the sensitivity of the meter head is high, it can be demagnetized, the hairspring can be replaced, or the brake coil can be rewound.
Clean transfer switch movable contacts, desoldering or re-soldering of virtual soldering.
2. DC voltage part
The adjustment of the DC voltage circuit can only be carried out after the adjustment of the current circuit. During adjustment, it is carried out step by step from the small amount limit to the large amount limit. The common resistance related to DC current cannot be adjusted any more.
3. AC voltage part
The adjustment of the AC voltage part is mainly on the rectifier element, such as the breakdown, damage, and reverse resistance reduction of the rectifier element. When replacing, choose a tube with close to the original characteristics. Likewise, anything related to DC current and DC voltage cannot be reset.
4. Resistor part
Replace the battery if it is low. Clean the contact points if they are rusted. It is necessary to lightly sand them with fine sandpaper and add Vaseline thinly.
The electromagnetic clip should have sufficient elasticity. When adjusting, start from the R*1 gear to the maximum gear. Any resistance related to the current and voltage loops is not allowed to be
