14 unique tips for using a multimeter

We all know that the multimeter is an indispensable and common maintenance tool for electrical workers. The correct use of the multimeter can not only make our work more efficient, but also improve the safety and efficiency of our work.

1. Before using the multimeter, you should first perform "mechanical zero adjustment";

2. Do not touch the metal part of the test lead with your hands during the measurement process to ensure both accurate measurement and personal safety;

3. In complex environments, you need to pay attention to the impact of external magnetic fields on the multimeter;

4. To improve the measurement accuracy, try to keep the multimeter pointer in the middle position when measuring. The range should be appropriate, and the needle should be deflected more than half. When selecting the range, if the size of the measurement cannot be estimated in advance, try to choose a larger range, and then gradually change to a smaller range according to the deflection angle until the pointer deflects to about 2/3 of the full scale;

5. When using a multimeter to test components with positive and negative polarity such as transistors and electrolytic capacitors, pay attention to the polarity relationship. Remember black is negative, and the black lead in the meter is connected to the "+". The red test lead is the positive pole, and the black test lead is the negative pole, but the black test lead on the resistance block is connected to the positive pole of the internal battery;

6. If the multimeter needs to change gears, disconnect the test leads first, and then measure after changing gears. Do not change gears when measuring, and turn it to neutral after measuring. Do not turn the selection knob arbitrarily during measurement, especially when measuring high voltage (such as 220V) or large current (such as 0.5A), so as to avoid arcing and burning the switch contacts. After measuring, turn the range selection switch to the "•" position;

7. When measuring resistance, zero adjustment must be performed each time the gear is changed. If zero adjustment cannot be performed, replace the battery. Zero adjustment is required before measuring R, and zero adjustment is required before changing gears. When measuring resistance, the conversion switch should be turned to the resistance block, the two test leads should be short-circuited, and the "Ω" zero adjustment potentiometer should be turned to make the pointer point to zero ohms before measuring. Every time the resistance block is changed, the ohm zero point should be readjusted;

8. After using the multimeter, the conversion switch should be set to the maximum AC voltage;

9. If the multimeter is not used for a long time, the internal battery should be removed to prevent the battery from corroding other components in the meter;

10. Check the range before measuring. Do not measure without checking. Every time you pick up the test lead to measure, be sure to check whether the measurement category and range selection switch are in the right position. For safety, you must develop this habit;

11. The dial should be level and the reading should be correct. The multimeter should be rotated horizontally and the line of sight should be facing the needle when reading;

12. Measure R without charging, and measure C with discharge first. It is strictly forbidden to measure resistance when the circuit being tested is charged. When checking large-capacity capacitors on electrical equipment, the capacitors should be short-circuited and discharged before measuring;

13. When measuring I, connect in series; when measuring U, connect in parallel. When measuring current, connect the multimeter in series to the circuit being measured; when measuring voltage, connect the multimeter in parallel to both ends of the circuit being measured.

14. Do not reverse the polarity and make it a habit to use one hand. When measuring current and voltage, pay special attention to the polarity of the red and black test leads. Do not reverse the polarity of the leads and make it a habit to use one hand to ensure safety.