How to use the commonly used functions of the multimeter
1. Measure the AC voltage: adjust the multimeter to the AC 600V gear (some are 750V gear), and then insert the multimeter pen into the household socket, and the multimeter display will display the measured voltage value
2. DC voltage test: Take a new 1.5V battery that is common 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 to the negative pole of the battery, and you can see that the multimeter shows 1.5V
3. Measure the resistance. Adjust the gear of the multimeter to the resistance gear of 200 ohms, and then touch the test leads to both ends of the resistance to be measured, and then the screen will display the resistance value of the measured resistance
4. On-off measurement: Adjust the multimeter to the buzzer position and connect the two test leads together, or connect them to both ends of the cable we need to test. If the cable is connected, the buzzer will sound at this time, otherwise it will not work.
When using a multimeter, you must pay attention to the following points:
1. Check the block first when measuring, and measure without looking
Every time you pick up the test lead and prepare to measure, be sure to check whether the measurement category and range selection switch is in the correct position. To be safe, this habit must be formed.
2. Measure without shifting the gear, and shift to neutral after the measurement
During the measurement, the selection knob cannot be moved arbitrarily, especially when measuring high voltage (such as 220V) or high current (such as 0.5A), so as not to generate arc and burn out the contacts of the transfer switch. After the measurement, the range selection switch should be turned to the "•" position.
3. Measure R without charge, measure C and discharge first
It is strictly forbidden to measure resistance when the circuit under test has points. When checking large-capacity capacitors on electrical equipment, the capacitors should be short-circuited and discharged before measurement.
4. The test I should be connected in series, and the test U should be connected in parallel
When measuring current, the multimeter should be connected in series in the circuit under test; when measuring voltage, the multimeter should be connected in parallel at both ends of the circuit under test.
5. The polarity is not reversed, one hand becomes a habit
When measuring current and voltage, special attention should be paid to the polarity of the red and black test leads not being reversed, and the habit of one-handed operation must be developed to ensure safety.
