Measurement and precautions of the capacitance range of the multimeter
There are two holes in the lower left gear of the digital multimeter, with Cx written on them. Simply insert the capacitor component to be measured into them and you can proceed with the measurement. If there are capacitors with polarity, be sure to pay attention to the positive and negative poles
Capacitance refers to the amount of charge stored at a given potential difference; Denoted as C, the international unit is Farad (F), a physical quantity that characterizes the ability of a capacitor to hold charge.
1 Farad (F)=1000 millifarads (mF)=1000000 microfarads (μ F)
1 microfarad (μ F)=1000 nanofarads (nF)=1000000 picofarads (pF)
How to judge the quality of capacitors?
Using a pointer type multimeter with an ohm range (the range is adjusted according to the battery capacity), first discharge the capacitor, and then touch the two pins of the capacitor with the two probes. At this time, the pointer of the meter will quickly swing and return to the starting position. Conversely, touching the pointer again will swing further and quickly return to the original position. If the pointer swings and cannot return to its original position, then the capacitor is leaking (it is normal for large capacity electrolytic capacitors to have slight leakage). If the pointer doesn't move, it means the capacitor is broken (the capacity is too small to be measured by several PFs, but I can measure small capacitors with capacities of 3N3, 4N7, etc. with 10K gear).
Method for measuring whether a capacitor leaks electricity
For capacitors above 1000 microfarads, they can be quickly charged using the R × 10 Ω range and the capacitance can be initially estimated. Then, switch to the R × 1k Ω range and continue measuring for a while. At this point, the pointer should not return, but should stop at or very close to ∞, otherwise there will be a leakage phenomenon. For some timing or oscillating capacitors below tens of microfarads (such as oscillating capacitors in color TV switch power supplies), the leakage characteristics are very high. As long as there is a slight leakage, they cannot be used. At this time, they can be charged in the R × 1k Ω range and then switched to the R × 10k Ω range to continue measuring. Similarly, the pointer should stop at ∞ and should not return.
