Tips for testing electronic components with a multimeter

　　The following is a brief introduction to the techniques of testing some electronic components with a multimeter.
　　1) Resistance test
　　Chip resistors are generally printed with resistance identification characters, such as 103 (resistance value is 10K), 102 (resistance value is 1K). Use a multimeter to test the resistance range and compare it with the marked value to know whether it is normal.

　　2) Capacitance test.
　　Many digital multimeters have a capacitance test position. Short-circuit the capacitor first to discharge, adjust it to the capacitance test position, and then connect the capacitor to be tested to the two dedicated test ports for the capacitor. Then the capacity can be read. If Only roughly determine whether the capacitor is good or bad. Use the resistance setting or buzzer setting to test. The capacitor should have no detectable resistance value (infinity) or the resistance will change from small to large and then to infinity, then it is normal.

　　3) The diode test
　　is based on the unidirectional conductivity of the diode. Use the buzzer setting. Connect the red and black pens casually first. If there is continuity (there is a numerical display), the red pen is connected to the anode of the diode, the black pen is connected to the cathode, and the red pen is connected to the cathode. When the black ratio is reversed, there should be no displayed value (just like the display content in the default untested state). In this way, it can be judged as normal after testing twice, otherwise it is abnormal.

　　4) Inductance test.
　　Some multimeters have an inductance test setting, which can test the inductance. The method is similar to that of testing capacitance. I will not go into details. If there is no inductance test function, you can only use the buzzer setting or the resistance setting to test whether the inductor is open circuit (normal inductance). The multimeter will make a sound when testing with the buzzer setting). If the inductor is short-circuited, it cannot be determined. There is a special capacitance and inductance meter for testing, and the LCR bridge is the best to use.

　　5) Transistor test:
　　The internal structure of a triode is close to that of a diode, and the judgment method is similar to that of a diode, so it will not be introduced here.