Discrimination of the polarity of electrolytic capacitors

The polarity of the electrolytic capacitor can be measured by the resistance barrier of the multimeter.

We know that the leakage current of the electrolytic capacitor is small (the leakage resistance is large) when the positive electrode of the electrolytic capacitor is positive (the black pen in the resistance gear), and the negative end power is negative. Conversely, the leakage current of the electrolytic capacitor increases (the leakage resistance decreases).

When measuring, it is assumed that a very "+" pole is first connected to the black pen of the multimeter, the other is connected with the red pen of the multimeter, the scale of the stop of the needle is recorded (the value of the needle is large), and then the capacitor is discharged (both the two lead lines are touched), and the two forms are adjusted and measured again. In the two measurement, the position of the last stop of the watch pin is on the left (the resistance value is large). The black pen is connected with the positive pole of the electrolytic capacitor.

The best choice is R*100 or R*1K. Use the multimeter to judge the quality of the capacitor.