Multimeter failure and reasons
The multimeter is used in many occasions and is used frequently, and the following faults and causes often occur:
1. There is no indication for the DC current gear. The meter head may be short-circuited or open, the resistance connected in series with the meter head is damaged or desoldered; the step switch is in poor contact;
2. There is no indication of DC voltage. The common contact of the switch in the voltage part is unsoldered, the additional resistance of the minimum range is disconnected or damaged; the transfer switch is in poor contact, etc.;
3. AC voltage gear failure. The indication value is extremely small or the reading is about half smaller, etc., indicating that the rectifier components in the table are damaged or broken down;
4. There is no indication when measuring resistance. The lead of the common contact point of the transfer switch is disconnected, the battery fails, the zero point adjustment potentiometer is damaged, etc., and a certain range is blocked, which is because the contact point of the transfer switch is in poor contact, or the series resistance is disconnected, etc.
Sometimes the magnetoelectric watch head is damaged due to carelessness during use, such as the misalignment of the hairspring, mechanical imbalance, coil disconnection, etc., the indication is abnormal, the hands are wobbly, and the error is too large.
