Introduction to the Operation Steps of a Digital Multimeter
(1) Resistance measurement. Adjust the conversion switch to the Ω position and connect the measuring probe to both ends of the resistor to display the corresponding reading. If the maximum value "1" (overflow symbol) is displayed, it must be adjusted to the high resistance value position until it is displayed as a valid value.
To ensure the accuracy of the measurement, it is best to disconnect one end of the resistor when measuring resistance on the road, in order to avoid forming a loop in the circuit and affecting the measurement results.
Attention: Online measurement is not allowed when powered on. Before measurement, the power must be cut off and the large capacity capacitor must be discharged.
(2) DCV "refers to direct current voltage measurement. The probe test end must be in reliable contact with the test end (parallel measurement). In principle, the measurement should be gradually adjusted from the high voltage gear to the low voltage gear until it reaches 1/3 to 2/3 of the displayed value of that gear. At this point, the displayed value is a relatively accurate one.
Attention: It is strictly prohibited to measure high voltage in low voltage mode. It is not allowed to adjust the transfer switch while it is powered on.
(3) ACV "AC voltage measurement. The probe test end must be in reliable contact with the test end (parallel measurement). In principle, the measurement should be gradually adjusted from the high voltage gear to the low voltage gear until it reaches 1/3 to 2/3 of the displayed value of that gear. At this point, the displayed value is a relatively accurate one.
Attention: It is strictly prohibited to measure high voltage in low voltage mode. It is not allowed to adjust the transfer switch while it is powered on.
(4) Diode measurement. Turn the conversion switch to the diode position, connect the black probe to the negative terminal of the diode, and connect the red probe to the positive terminal of the diode to measure the forward voltage drop value.
(5) Measurement of transistor current amplification factor hEF. Turn the conversion switch to the "hFE" position, select the "PNP" or "NPN" position according to the tested transistor, insert the transistor correctly into the test socket, and the "hee" value of the transistor can be measured.
(6) Open circuit detection. Turn the conversion switch to the gear with the buzzer symbol, and ensure that the test probe contacts the test point reliably. If both are below 20 ± 10 Ω, the buzzer will sound, indicating that the circuit is connected. If it does not sound, the circuit is not connected.
Attention: Testing is not allowed when the measured circuit is powered on.
(7) DCA "direct current measurement. Insert the red probe into the mA socket at 200mA; At 200mA
Insert the red probe into socket A, and the test end of the probe must be in reliable contact with the test end (measured in series). In principle, the measurement should be gradually adjusted from the high current gear to the low current gear until it reaches 1/3 to 2/3 of the displayed value of that gear. At this point, the displayed value is a relatively accurate one.
Attention: It is strictly prohibited to measure high current in low current mode. It is not allowed to adjust the transfer switch while it is powered on.
(8) ACA stands for AC current measurement. Insert the red probe into the mA socket at 200mA; At 200mA, the red probe should be inserted into socket A, and the test end of the probe must be reliably in contact with the test end (measured in series). In principle, the measurement should be gradually adjusted from the high current gear to the low current gear until it reaches 1/3 to 2/3 of the displayed value of that gear. At this point, the displayed value is a relatively accurate one.
