How to test the quality of 25 volts 6800 microfarad capacitors with a multimeter
Can be measured with a multimeter. For digital meters, a special capacitance gear can be used for measurement. In addition, it can also be measured by the resistance file of the pointer meter.
It is relatively simple to measure with a digital meter, and you can read it directly by measuring. Since most of the meters cannot measure the capacitance of more than 200μF, it can be measured in series, and then the capacity of the measured capacitance can be estimated by the meter.
Below are the results I measured with a 150µF capacitor. In order to reduce the error, first measure the actual capacity of this capacitor, the measured value is only 131.2μF, and then string it together with the 6800μF capacitor. Then the total capacity measured is C total:
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It is exactly in line with the results of the calculus. It shows that the capacitor is good and there is no problem with the capacity.
In fact, the capacitance file of the multimeter is not very accurate, so the value of the difference is not large, and the capacitance is considered to be good.
In addition, it can also be measured by the resistance file of the pointer multimeter. Due to the large capacity of this capacitor, it should be measured with the low resistance of Rx1 or Rⅹ10. For example, when using the Rx1 gear of the MF47 meter, the moment the test pen touches the capacitor pin, the pointer swings to about 60Ω.
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If the swing is too small, it means that the capacity is insufficient. If it does not swing or the pointer cannot return to zero after a large deflection, the capacitor is damaged. There will be differences between different multimeters in terms of swing, but not too much.
After measuring the capacity, you can change the gear to Rx1K or Rx10K to detect leakage, and the pointer should gradually return to zero. If the resistance value below several hundred KΩ is always displayed, it means that the capacitor has serious leakage and can no longer be used. When measuring the pointer meter, pay attention to the polarity of the capacitor. The red test lead must be connected to the negative electrode of the capacitor, otherwise there will be leakage.
In addition, be sure to discharge the capacitor before detecting it.
Responsible editor: CC
