How to use the commonly used functions of a multimeter?
The most commonly used multimeter nowadays is the digital multimeter. The following introduces several of its most commonly used functions:
Measuring AC voltage: Adjust the multimeter to the AC 600V gear (in some cases, it is the 750V gear). Then insert the test leads of the multimeter into a household socket. At this time, the display screen of the multimeter will show the measured voltage value.
DC voltage testing: Taking a common new 1.5V battery at home as an example, adjust the multimeter to the DC voltage gear. Then connect the red test lead to the positive pole of the battery and the black test lead to the negative pole of the battery. You can see that the multimeter displays 1.5V.
Measuring resistance: Adjust the gear of the multimeter to the 200-ohm resistance gear. Then touch the test leads to both ends of the resistance to be measured, and the screen will display the resistance value of the measured resistance.
Continuity measurement: Adjust the multimeter to the buzzer gear. Connect the two test leads together, or connect them to both ends of the cable that needs to be tested. If the cable is continuous, the buzzer will ring; otherwise, it is not continuous.
There are several precautions that must be noted when using a multimeter:
Check the gear before measuring, and do not measure without checking.
Every time you pick up the test leads and are ready to measure, be sure to double-check whether the measurement category and the range selection switch are in the correct position. For safety reasons, you must develop this habit.
Do not change the gear during measurement, and set the range selection switch to the "•" position after measurement.
Do not arbitrarily turn the selection knob during measurement, especially when measuring high voltage (such as 220V) or large current (such as 0.5A), to avoid generating arcs and burning out the contacts of the conversion switch. After the measurement is completed, the range selection switch should be turned to the "•" position.
Do not measure resistance when the circuit is energized, and discharge the capacitor first when measuring the capacitor.
It is strictly prohibited to measure resistance when the measured circuit is energized. When checking large-capacity capacitors on electrical equipment, the capacitor should be short-circuited and discharged before measurement.
Connect in series when measuring current and connect in parallel when measuring voltage.
When measuring current, the multimeter should be connected in series in the measured circuit; when measuring voltage, the multimeter should be connected in parallel at both ends of the measured circuit.
Do not connect the polarities reversely, and develop the habit of operating with one hand.
When measuring current and voltage, pay special attention not to connect the polarities of the red and black test leads reversely, and you must develop the habit of operating with one hand to ensure safety.
