What are the detection methods for diodes?

What are the detection methods for diodes?

When using a multimeter to detect a diode, the black lead with a smaller value is connected to the positive terminal, while the red lead is connected to the negative terminal. If the forward and reverse resistances are both infinite, it indicates that the diode has been opened and damaged; If both the forward and reverse resistances are 0, it indicates that the diode has been short circuited and damaged. Under normal circumstances, the forward resistance of germanium diodes is approximately 1.6k Ω.

When using a digital multimeter to measure a diode, the red lead is connected to the positive pole of the diode, and the black lead is connected to the negative pole of the diode. At this point, the measured resistance value is the forward conduction resistance of the diode, which is exactly the opposite of the probe connection method of a pointer multimeter.

It is more convenient to use the diode block of a digital multimeter to detect diodes: place the digital multimeter in the diode block, and then connect the negative pole of the diodes to the black lead of the digital multimeter, and the positive pole to the red lead. At this time, the positive voltage drop value of the diode can be displayed on the display screen. diodes made of different materials have different forward voltage drop values: 0.55-0.7V for silicon diodes and 0.15-0.3V for germanium diodes. If the display screen shows "0000", it indicates that the pipe has been short circuited; If "0L" or "overload" is displayed, it indicates that the diodes is in an open circuit or reverse state internally. At this time, the probe can be adjusted for retesting.