Detailed Information and Explanation of Multimeter Usage Mnemonics
1. Before measuring, check the shield. If you don't check, don't measure. Every time you pick up the meter probe to prepare for measurement, be sure to double-check whether the measurement category and range selection switch are set to the correct position. For safety, it is essential to develop this habit.
2. Measure without engaging the gear, and engage neutral gear after measurement
During measurement, do not arbitrarily adjust the selection knob, especially when measuring high voltage (such as 220V) or high current (such as 0.5A), to avoid generating arcs and burning out the transfer switch contacts. After measurement, turn the range selection switch to the "•" position.
3. The dial should be horizontal, and the readings should be aligned
When using a multimeter, rotate it horizontally, and direct your line of sight directly at the pointer when reading the readings.
4. The measuring range should be appropriate, with the needle deflection being more than half of the full scale
When selecting a measuring range, if the magnitude of the quantity being measured cannot be estimated in advance, one should choose a larger range as much as possible. Then, based on the size of the deflection angle, gradually switch to a smaller range until the pointer deflects to about two-thirds of the full scale.
5. Measure R when it is not charged, and discharge C before measuring it
It is strictly prohibited to measure resistance when the circuit under test is live. When inspecting large-capacity capacitors on electrical equipment, the capacitors should be short-circuited and discharged before measurement.
6. Before measuring R, adjust the zero point first. When changing gears, adjust the zero point again
When measuring resistance, first rotate the switch to the resistance setting, connect the two probes in a short circuit, and adjust the "Ω" zero potentiometer until the pointer indicates zero ohms before proceeding with the measurement. Each time you change the resistance setting, you should readjust the ohms zero point.
7. Remember clearly about the black negative, and connect the black wire inside the meter to the "+" terminal
The red probe is the positive pole, and the black probe is the negative pole. However, when in the resistance mode, the black probe is connected to the positive pole of the internal battery.
8. Measure I in series, measure U 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 two ends of the circuit being measured.
9. Don't reverse the polarity, and get used to using one hand
When measuring current and voltage, special attention should be paid to ensuring that the polarities of the red and black probes are not reversed, and it is essential to develop the habit of operating with one hand to ensure safety.
