Diagram of gear symbols on digital multimeter

It consists of an LCD display, a main power switch, a precise measurement switch, a DC ammeter detection socket, a power capacitor socket and a transistor socket.

The top of the digital multimeter is an LCD screen, which can directly display three and a half digits. The decimal place will automatically move according to the need, and the minus sign "-" will automatically appear according to the measurement result. Below the display is the operation panel, and in the middle of the control panel is the measurement switch. You only need to turn a knob to select the measurement range, which is convenient to use. The measurement switch indicator is printed in red, green, and white according to the measurement type, so it is not easy to confuse.

There are 4 test ammeter sockets under the control panel. The black one is the negative ammeter socket (also called the common terminal socket) "COM". The three red ones are the positive ammeter sockets, which are the voltage resistance measurement socket "VΩ", the mAh current measurement socket "mA", and the picoampere current measurement socket "A". As shown in the figure below. When using, usually plug the black ammeter into the "COM" socket, and the red ammeter into the corresponding positive ammeter socket according to the measurement requirements.

The upper left of the control panel is equipped with the main power switch (POWER) of the entire machine. Press it to turn on, and press it again to make it pop up to turn off. The upper right of the control panel is the transistor socket. The left side of the socket is marked with "PNP". When testing a PNP transistor, plug it into this socket. The right side of the socket is marked with "NPN". When testing an NPN transistor, plug it into this socket, as shown in the figure below.