1. Testing capacitors below 10pF: Due to the extremely small capacitance of fixed capacitors below 10pF, measurements can only be qualitative, checking for leakage, internal short circuits, or breakdown. When measuring, use the multimeter's R×10k range and connect the two test leads to any two terminals of the capacitor. The resistance should be infinite. If the resistance reading (the needle moves to the right) is zero, it indicates that the capacitor is leaking or has internally shorted.
2. Testing fixed capacitors 10PF～001μF: Determine their quality by observing the charging phenomenon. Use the multimeter on the R×1k range. Both transistors have a β value of 100 or above, and the穿透 current should be low. You can use composite transistors made from models like 3DG6. Connect the red and black probes of the multimeter to the emitter e and collector c of the composite transistor, respectively. Due to the amplification effect of the composite transistor, the charging and discharging process of the measured capacitor is amplified, increasing the swing of the multimeter pointer, making it easier to observe. Aviation ground power 2, 36V aviation power supply 1, 400HZ variable frequency power supply 7, 115/200V power supply 2, 27V DC power supply 5, 400HZ power supply 12, aviation power supply
Note: During testing operations, especially when measuring smaller capacitance values, it is necessary to repeatedly switch the contact of the capacitor leads between points A and B to clearly observe the movement of the multimeter's needle. For fixed capacitors above 001μF, the R×10k range on the multimeter can be used to directly test for the capacitor's charging process, internal short circuits, or leakage. The capacity of the capacitor can be estimated by observing the extent to which the needle swings to the right.
