The multimeter is a universal device designed for various measurements: voltage, resistance, current, even the simplest wire breakage tests. With it, you can even measure the suitability of the battery.
Instructions
Step 1
Determine if your multimeter has a diode test function, if so, then connect the probes, the diode will ring in one direction, and not in the other. If this function is not available, set the multimeter switch to 1kΩ, select the resistance measurement mode. Check the diode. When you connect the red lead of the multimeter to the anode of the diode and the black lead to the cathode, observe its forward resistance.
Step 2
Draw conclusions about the state of the diode when connected back. At the current limit, the resistance should be so high that you will not see anything. If a punctured diode is used, its resistance in either direction will be zero, and if it is cut off, then the resistance will take on an infinitely large value in any direction.
Step 3
Check the diode with a multimeter. This can be done by connecting the negative and positive poles of the ohmmeter, first set it on the Rx100 scale, respectively, to the negative (cathode) and positive (anode) terminals of the diode. The result of resistance measurements should be from five hundred to six hundred ohms, if the diodes are ordinary (silicon), or from 200 to 300 ohms, if they are germanium. If the diodes are rectifying, then their resistance will be lower than usual due to their large size. With this method, you can quickly determine the health of a diode.
Step 4
Switch the ohmmeter for diode leakage or short circuit to the high impedance scale, swap the diode leads. In the event of increased leakage or short circuit, the resistance will be low. For germanium diodes, it can range from 100 kilo-ohms to 1 mega-ohm. For silicon diodes, this value can reach thousands of megohms. Please note that rectifier diodes have much higher leakage currents. And some diodes may have a lower return resistance, but work fine in some circuits.
