The usage steps of a multimeter. How to use the hFE function of a multimeter?
Steps for Using a Multimeter:
Preparation work: First, ensure that the battery of the multimeter has sufficient power and check for any damage. Check and select the correct measurement range.
Measuring resistance: Turn the knob of the multimeter to the Ω position and touch the measurement terminals of the resistance. If it is a high resistance value, select a higher measurement range, and if it is a low resistance value, select a smaller measurement range.
Measuring voltage: Turn the knob of the multimeter to the V position and select an appropriate voltage range. Connect the red test lead to the positive pole of the measured voltage and the black test lead to the negative pole, and read the voltage value on the display screen.
Measuring current: Turn the knob of the multimeter to the A position and select an appropriate current range. Connect the red test lead to the current input terminal and the black test lead to the input return terminal. Turn on the circuit and read the current value on the display screen.
Measuring capacitance: Turn the knob of the multimeter to the F position and select an appropriate capacitance range. Connect the red test lead to the positive pole of the capacitor and the black test lead to the negative pole, and read the capacitance value on the display screen.
Measuring diodes: Turn the knob of the multimeter to the hFE position and select the NPN or PNP type. Connect the red test lead to the base and the black test lead to the collector, and read the hFE value on the display screen.
Other measurements: According to needs, the multimeter can also be used to measure other quantities such as frequency, temperature, induced voltage, etc.
Method of Using the hFE Function of a Multimeter:
hFE refers to the DC current amplification factor of a transistor, which is the ratio between the change of the base current and the change of the collector current when the transistor is in the amplification state. Measuring hFE is an important part of transistor detection and is also one of the important functions of a multimeter.
Preparation work: First, determine whether the transistor to be tested is of the PNP or NPN type.
Select the test mode: Select the hFE position with the knob of the multimeter.
Connect the test circuit: Connect the red test lead to the base of the transistor and the black test lead to the collector.
Start the test: Turn on the switch of the transistor to be tested and observe the hFE value on the multimeter.
Interpretation of the results: Judge whether the transistor is working properly according to the hFE value displayed on the multimeter.
Generally, the hFE of an NPN transistor should be between 100 and 1000, and the hFE of a PNP transistor should be between 50 and 500.
