We all know that the multimeter is an indispensable and common maintenance tool for electrical workers, and the correct use of the multimeter can not only make our work more effective, but also improve the safety and efficiency of our work.
1. Before using the multimeter, the "mechanical zero adjustment" should be carried out first;
2. Do not touch the metal part of the pen with your hands during the measurement process, which not only ensures the accuracy of the measurement, but also ensures personal safety;
3. In complex environments, it is necessary to pay attention to the influence of external magnetic fields on multimeters;
4. In order to improve the measurement accuracy, try to make the pointer of the multimeter in the middle position when measuring. The measuring range should be appropriate, and the needle should be more than half deflected. Select the range, if the measured size cannot be estimated in advance, you should try to choose a larger range, and then gradually change to a smaller range according to the size of the deflection angle, until the pointer is deflected to about 2/3 of the full scale;
5. When using a multimeter to test transistors and electrolytic capacitors and other components with positive and negative polarity, pay attention to the polarity relationship. The black negative should be remembered clearly, and the black inside the table is connected with "+". The red meter pen is the positive pole and the black meter pen is the negative pole, but the electric blocking is the positive pole of the black meter pen connected to the internal battery;
6. If the multimeter needs to shift gears, the meter pen should be disconnected first, and then measured after the gear change. The measurement does not dial the gear, and the neutral gear is dialed after the measurement is completed. The selection knob cannot be arbitrarily toggled during the measurement, especially when measuring high voltage (such as 220V) or large current (such as 0.5A), so as not to generate arcs and burn out the transfer switch contacts. After the measurement, the range selector switch should be dialed to the " " position;
7. When measuring the resistance, every time the gear is changed, it must be adjusted to zero. Replace the battery with a new battery when the dial is not zero. The test R is adjusted to zero first, and the gear shift needs to be adjusted to zero. When measuring the resistance, the transfer switch should be first screwed to the electrical barrier, the two table pens should be shorted, and the "Ω" should be rotated to zero potentiometer, so that the pointer points to zero ohm before measuring. Each time the electrical barrier is replaced, the ohmic zero point should be readjusted;
8. After the multimeter is used, the transfer switch should be placed in the maximum gear of AC voltage;
9. If it is not used for a long time, the battery inside the multimeter should be removed to avoid battery corrosion of other devices in the meter;
10, measurement first look at the block, do not look at the measurement. Each time you pick up the pen and set up a measurement, be sure to check again whether the measurement category and the range selector switch are dialed correctly. For safety, this habit must be developed;
11. The dial should be horizontal and the readings should be corrected. The multimeter should be rotated horizontally, and the line of sight should be facing the needle when reading;
12, the measurement of R is not charged, the measurement of C is discharged first. It is strictly forbidden to measure the resistance in the case of the circuit under test with dots. When inspecting the bulk capacitors on electrical equipment, the capacitor should be short-circuited and discharged before measuring;
13. Test I should be connected in series, and test U should be connected in parallel. When measuring current, the multimeter should be connected in series in the circuit under test; when measuring the voltage, the multimeter should be connected in parallel at both ends of the circuit under test;
14, polarity does not reverse, one-handed habit. When measuring current and voltage, special attention should be paid to the polarity of the red and black pens, and it is necessary to develop the habit of one-handed operation to ensure safety.
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