What is the method of measuring capacitance with multimeter
Use the resistance ohm file of the digital multimeter, and discharge the measured capacitor before measuring to prevent damage to the digital multimeter. The two stages of the capacitor are not connected, it is best to connect them with an appropriate resistor.
Capacitance measurement: use the resistance file, select the appropriate range according to the capacitance capacity, and pay attention to the black test lead of the electrolytic capacitor should be connected to the positive pole of the capacitor when measuring.
①. Estimate the size of the capacitor of the microwave method: it can be judged according to the maximum amplitude of the pointer swing by experience or referring to the standard capacitor of the same capacity. The referenced capacitors do not need to have the same withstand voltage value, as long as the capacity is the same. For example, a 100μF/250V capacitor can be used as a reference to estimate a 100μF/25V capacitor. As long as the maximum swing of their pointers is the same, it can be concluded that the capacity is the same.
②. Estimate the capacitance of picofarad capacitors: R×10kΩ should be used, but only capacitance above 1000pF can be measured. For a capacitance of 1000pF or slightly larger, as long as the hands of the watch swing slightly, the capacity can be considered sufficient.
③. To measure whether the capacitor is leaking: for a capacitor above 1,000 microfarads, you can first use the R×10Ω file to quickly charge it, and initially estimate the capacitor capacity, and then change to the R×1kΩ file to continue measuring for a while. At this time, the pointer does not It should return, but stop at or very close to ∞, otherwise there will be leakage. For some timing or oscillating capacitors below tens of microfarads (such as the oscillating capacitors of color TV switching power supplies), the requirements for their leakage characteristics are very high, as long as there is a slight leakage, they cannot be used. At this time, they can be charged at the R×1kΩ level. Then use the R×10kΩ file to continue the measurement, and the hands should stop at ∞ and should not return.
How to test the electric fan capacitor with a multimeter
1. First prepare a multimeter.
2. Short-circuit the capacitor of the electric fan and discharge the capacitor first.
3. Then insert the red connector of the multimeter into the CX position, as shown in the figure.
4. Turn the dial and set the multimeter to 200.
5. Then connect the red connector to the capacitor of the electric fan.
6. At this time, the reading of the ammeter changes, indicating that the capacitor is good, otherwise the capacitor will be broken.
