In the process of using various electronic components, once damaged, it will affect the overall operation and performance. As an indispensable key to many electronic product equipment, its quality determines the operation and life of the equipment. How do we check the quality of ceramic capacitors in our daily use? The following are commonly used measurement methods.

Detect ceramic capacitors below 10pF—Because the capacity of fixed capacitors below 10pF is too small, measuring with a multimeter can only qualitatively check whether there is leakage, internal short circuit or breakdown. When measuring, you can choose a multimeter R×10k block, and use two meter pens to connect the two pins of the capacitor at will, and the resistance should be infinite. If the measured resistance value (the pointer swings to the right) is zero, it means that the capacitor is damaged by leakage or internal breakdown.

Detect whether the 10PF～0.01μF fixed capacitor is charging, and then judge its quality. The multimeter selects R×1k gear. The β value of the two transistors is above 100, and the penetration current is small. 3DG6 and other types of silicon transistors can be used to form a composite tube. The red and black test leads of the multimeter are respectively connected to the emitter e and collector c of the composite tube.

Due to the amplification effect of the composite triode, the charge and discharge process of the ceramic capacitor under test is amplified, so that the pointer swing of the multimeter is enlarged, which is convenient for observation. It should be noted that during the test operation, especially when measuring smaller-capacity ceramic capacitors, it is necessary to repeatedly change the contact points A and B of the capacitor pin to be tested, to clearly see the swing of the multimeter pointer.

Since the capacity of ceramic capacitors is generally relatively small (PF level), it is difficult to judge by charging and discharging with an analog multimeter. It is recommended to use the capacitance block test of a digital multimeter.