Things to note when measuring DC current with a multimeter
The DC current range of a multimeter is a multi range DC voltmeter. The parallel connection of a closed circuit voltage divider resistor in the meter head can expand its voltage range. The DC voltage range of a multimeter is a multi range DC voltmeter. Connecting a voltage divider resistor in series with the meter head can expand its voltage range. The corresponding range varies depending on the voltage divider resistor. The head of a multimeter is a magneto electric measuring mechanism, which can only measure AC power by converting AC power to DC power through diodes.
1, Perform mechanical zeroing.
2, Choose the appropriate range gear.
3, When using a multimeter to measure current in the current mode, the multimeter should be connected in series with the sub measured circuit, because only a series connection can ensure that the current flowing through the ammeter is the same as the measured branch current. When measuring, the tested branch should be disconnected and the red and black probes of the multimeter should be connected in series between the two points where the quilt is disconnected. Special attention should be paid to the fact that current recording can be connected to the sub test circuit, which is very dangerous and can easily cause the multimeter to burn out.
4, Pay attention to the polarity of the measured electricity.
5, Correct use of scales and readings.
6, When selecting the 2.5A mode with DC current, the red probe of the multimeter should be inserted into the 2.5A measuring socket, and the range switch can be placed on any range of the DC current mode.
7, If the measured DC current is greater than 2.5A, the 2.5A range can be extended to 5A range. The method is very simple. The user can connect a 0.24 ohm resistor between the "2.5A" socket and the black probe socket, so that the gear becomes the 5A current gear. The 0.24A resistor used for connection should be a wire wound resistor of at least 2W. If the power is too low, it may burn out.
