Capacitance measurement with a multimeter - tips and tricks
Today I share with you a multimeter to measure capacitance capacity method, the method is very simple, since we want to measure capacitance, so just take out the multimeter first to observe the measurement of capacitance where the gear, need to replace the needle position, I only have the following chart in the hands of this multimeter, so can only be used as an example of the following this, in fact, there are many types of multimeter, like the second chart below and is a kind of, but Different multimeter measurement method is basically the same, learn a basically learnt!
In the picture above we can see in the lower left corner of the dial has a capital "F" sign, in fact, it means that the measurement of capacitance of the gear, is named after the capacitance of the international unit farad, the next step to rotate the meter needle to a range greater than the size of the capacitance measured, in fact, the closer the better, in order to facilitate the operation, we directly In order to facilitate the operation, we directly use the maximum range of the multimeter, in addition to the need to look at the position of the needle need to be changed, generally the position of the black pen has a fixed sign "COM", so we only need to change the position of the red pen on it, and capacitance of the symbol for the "C The symbol for capacitance is "C", and there is a "Cx" on the multimeter, so we can insert the red pen into the hole.
Next we can measure, the picture below shows a washing machine capacitor, this capacitor is relatively large, the withstand voltage value is also very high, but the capacity is not very large compared to the aluminium electrolytic capacitor, there is no positive and negative poles, so in the measurement of the two pens can be connected at will, but there is a point to be noted, that is, the hand can not be touched at the same time the two pens, which has an effect on the results of the measurement, if the operation is correct, then the red pen on the multimeter can be inserted into the hole. If the operation is correct, you can see the measured capacitance size on the multimeter, the capacitance in the video is labelled as 4uf, and the measured capacitance is 4.3uf.
The above kind of washing machine capacitor is not distinguishable polarity, it is easier to understand, but there is another kind of polarity capacitor, this kind of capacitor has polarity, if it is a new polarity capacitor, the long pin is positive, short is negative, welded on the board can be distinguished by the outer skin packaging, in short, it is polarity, so we use the multimeter to measure the size of the capacitance of it is not the same time we need to distinguish between the positive and negative pole Then when we measure its capacity with a multimeter, do we also need to distinguish between positive and negative poles? Light said useless, to actually test it, the following chart is in accordance with the normal understanding of the order of measurement, that is, the red pen connected to the positive pole, the black pen connected to the negative pole, at this time we can see in the multimeter display shows the size of the measured capacitance at this time for the 109 uf, in the number of the front there is no "-" sign!
Then we will replace the order of the capacitor pins, that is, the red pen connected to the negative terminal of the capacitor, the black pen connected to the positive terminal of the capacitor, and then take a look at the size of the capacitance measured at this time, the following chart is to replace the capacitance of the capacitance measured by the order of the capacitance pins of the capacitance of the size of the capacitance of the size of the measured at this time and the last time to measure out the size of the capacity of the size of the measurement of almost no difference, there is no "-" sign in front of the number. What difference, there is no "-" mark in front of the number, so we can think that in the multimeter to measure the size of the polarity capacitance and the order of the needle to connect has nothing to do!
