judging the quality of chip capacitors is a necessary skill for purchasing capacitors. electrolytic capacitor manufacturers have summed up two different judgment methods, one is to observe the appearance, size and color, and the other is to use digital bridge to detect.
if it is a chip capacitor with qualified quality, the appearance size should be consistent with the size marked on the outside or the size on the instruction manual and on the outer package. however, if you have a chip capacitor in hand, i find that the appearance size seems to have some changes, such as slight defects or slight cracks, then the appearance size is ok there will be some problems, which may indirectly indicate that there are some problems with this capacitor.
secondly, look at the tin feet. if there are black spots, defects, cracks, and uncoordinated proportion of the top and bottom of the tin feet, the quality can be roughly judged by naked eyes.
you can also see the color. if it is a normal factory capacitor, then the appearance color is uniform, and there will be no color difference such as blackening and graying in the same batch. but if you get a chip capacitor, the naked eye observation finds that the color on the outside has been blackened, even like the color of smoke, it may indicate that the capacitor has some color the problem is, and this kind of capacitor can not be installed in the installation, should be tested, if the test is not qualified, it means that there is a problem with the capacitor.
second: use digital bridge to test
the detection process is very simple, that is, directly adjust the bridge to the corresponding gear, and then use the bridge clamp to connect the two tin pins of the capacitor to short circuit. then observe the reading at this time. after the reading is stable, if the capacitance value is consistent with the reading in the instruction manual of the capacitor, or the deviation is very small within the normal error range, it means that the capacitance should have no problem.