What are the simple test methods for electrolytic capacitors?

What are the simple test methods for electrolytic capacitors? Use a pointer multimeter to check the electrical barrier of the electrolytic capacitor. The electrode of the electrolytic capacitor has polarity. When checking its quality, the pilot test holds the electrolytic capacitor with lower withstand voltage, and the electrical barrier should be placed at R×100 or R× 1k block, connect the red test to the negative end of the capacitor, and the black test to the positive end. At this time, the pointer of the multimeter will swing and then return to or near the zero position. Such an electrolytic capacitor is good. The larger the capacity of the electrolytic capacitor, the longer the charging time, and the slower the pointer swings back.

Use a pointer multimeter to estimate the capacitance and leakage current of the electrolytic capacitor. To test the leakage current of the electrolytic capacitor, the ×1k block of the multimeter should be selected. The closer the end point of the pointer swing of the multimeter is to the zero point of the pointer multimeter, the lower the leakage current. When testing large-capacity electrolytic capacitors, the swing speed of the pointer may be very slow. You can use the ×1 block to quickly charge the electrolytic capacitor until the pointer returns to zero.

Then adjust to the ×1k block. At this time, the indicator of the pointer may gradually increase. After the pointer stops, the leakage current of the electrolytic capacitor can be judged. The "resistance" of a genuine electrolytic capacitor with a capacitance of less than 1000uF should be greater than 2MQ (a multimeter with a center resistance of about 24kΩ in the ×10k block), otherwise, it indicates that the electrolytic capacitor has a large leakage current. Of course, the greater the capacitance, the greater the leakage current.

Use a pointer multimeter to judge the positive and negative s of electrolytic capacitors. Some electrolytic capacitors with lower withstand voltage. If the positive and negative s are not marked, it can be based on the fact that the leakage current is small when the positive connection is connected (the resistance value is large), and the leakage current is reversed. Big characteristics to judge.

This kind of pilot holding method makes it more difficult to distinguish the polarity of electrolytic capacitors with low leakage current, that is, electrolytic capacitors with better quality.