Multimeter Usage Mnemonics

Multimeter Usage Mnemonics

1. Check the range before measuring; do not measure without checking.

Every time you pick up the probes to prepare for measurement, make sure to double-check whether the measurement category and range selection switch are set correctly. For safety, this habit must be developed.

2. Do not change the range while measuring; switch to the off position after measuring.

Do not arbitrarily turn the selection knob during measurement, especially when measuring high voltage (like 220V) or large current (like 0.5A), to avoid generating electric arcs that could damage the switch contacts. After completing the measurement, switch the range selection to the “•” position.

3. Keep the dial level; read the values straight on.

When using an analog multimeter, it should be rotated horizontally, and your line of sight should be directly aligned with the needle.

4. Choose the appropriate range; the needle should deflect more than half.

When selecting a range, if the size of the measurement cannot be estimated in advance, it is advisable to select a larger range. For analog multimeters, based on the degree of deflection, gradually switch to a smaller range until the needle deflects to about two-thirds of the full scale.

5. Measure resistance (R) without power; discharge capacitors (C) before measuring.

It is strictly forbidden to measure resistance (R) in a live circuit. When checking large capacitors (C) on electrical devices, discharge the capacitor short-circuit before measuring.

6. Zero the meter before measuring resistance; readjust zero when changing ranges.

When measuring resistance, first turn the switch to the resistance setting, short the two probes, and adjust the “Ω” zero potentiometer until the needle points to zero ohms before measuring. Every time you change the resistance range, you should readjust the ohm zero point.

7. Remember the black negative; the black lead connects to “+” inside the meter.

The red probe is positive, and the black probe is negative, but in the resistance setting, the black probe connects to the positive terminal of the internal battery.

8. Measure current (I) in series; measure voltage (U) in parallel.

When measuring current (I), the multimeter should be connected in series with the circuit being measured; when measuring voltage (U), the multimeter should be connected in parallel across the circuit.

9. Do not reverse polarity; develop a habit of using one hand.

When measuring current and voltage, pay special attention to ensure the red and black probes are not reversed, and always develop the habit of using one hand to ensure safety.