How to Use a Multimeter: Key Tips

Correctly using a multimeter can quickly and accurately identify faults, and prevent damage to both electrical devices and the multimeter itself.

1. Check Range Before Measuring Every time you pick up the probes to measure, always double-check whether the measurement category and range selection switch are set correctly. For safety, this habit must be developed.

2. Do Not Change Range During Measurement Do not arbitrarily adjust the selection knob during measurement, especially when measuring high voltage (like 220V) or large current (like 0.5A), to avoid generating an arc, which could burn out the switch contacts. After measuring, set the range selection switch to the “•” position.

3. Keep the Dial Level, Align the Reading When using a multimeter, it should be rotated to a level position, and the line of sight should be directly aligned with the needle when reading.

4. Choose Appropriate Range, Needle Should Deflect Over Half When selecting a range, if you cannot estimate the size of the measurement beforehand, try to select a larger range first, then gradually switch to a smaller range based on the deflection angle, until the needle deflects about 2/3 of the full scale.

5. Do Not Measure Resistance While Powered, Discharge Capacitors First It is strictly forbidden to measure resistance when the circuit is live. When checking large capacitors on electrical equipment, discharge the capacitor before measuring. Click to download a wealth of engineering materials for free.

6. Adjust to Zero Before Measuring Resistance, Zero When Changing Range When measuring resistance, first turn the switch to the resistance range, short the two probes, and adjust the “Ω” zero potentiometer so that the needle points to zero ohms before measuring. Each time you change the resistance range, you should re-adjust the ohm zero point.

7. Remember Black is Negative, Black Connects to “+” Inside the Meter The red probe is positive, and the black probe is negative, but in resistance mode, the black probe connects to the internal battery’s positive terminal.

8. Measure Current in Series, Measure Voltage in Parallel When measuring current, the multimeter should be connected in series with the circuit being measured; when measuring voltage, the multimeter should be connected in parallel across the circuit.

9. Do Not Reverse Polarity, Develop a One-Handed Habit When measuring current and voltage, pay special attention not to reverse the polarity of the red and black probes, and always develop a one-handed operation habit to ensure safety.

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