Material preparation: multimeter.
1, measure the leakage with a multimeter.
First, keep the circuit energized, and turn the middle range of the multimeter to the voltage range. Touch the black stylus to the ground or zero line, and touch the red stylus to the place where the leakage is suspected. If the multimeter measures the voltage at this time, it means there is electricity leakage here.
2. Measure the short circuit with a multimeter.
It is necessary to cut off the power supply before measurement. Switch the multimeter to ohm range. Touch the ground wire with any probe, and touch the suspected short circuit test point with the other probe. If the resistance measured at this time is less than 5 ohms, it is short-circuited to ground.
Matters needing attention in the use of multimeter:
1, before measurement, check whether the pointer rotates flexibly or not, and then select the range of appropriate gear to measure according to the needs of the circuit under test.
2. When measuring, it should be noted that the error range between the instrument reading and the actual value should be within (0.05+0.005438+0)%.
3. Pay attention to prevent electric shock when measuring high voltage and current.
4. For small-capacity resistor or capacitor elements, special attention should be paid to the fact that the positive and negative terminals cannot directly contact the skin or clothes; Test large-capacity resistance or inductance components as close as possible to the body; For high-capacity and high-temperature electronic components, it is necessary to use insulation toolbox to operate.
5. When using the on-off gear of the multimeter, you must first disconnect the power supply and then switch gears;
6, don't make the meter contact with the metal part of the circuit under test, so as not to damage the parts in the table and affect the accuracy.
7. When the measured object has a large lead, lead it out and then connect it to the ground wire for testing;
8. Don't use multimeter in damp place, otherwise it will damp the internal parts and affect the performance and service life.
9. Don't disassemble the parts of multimeter at will to repair other faults!