The reason why there is no response when measuring capacitance with a multimeter
We know that a capacitor is made of an insulating plate between two pieces of metal. When a voltage is applied between two electrodes, there will be a charge. Therefore, when measuring, it must be discharged first and then tested. There should be the following reasons for the multimeter to measure the capacitance without any response.
1. The internal circuit of the capacitor is broken, and the capacity is invalid. This is quite common
2. The multimeter is damaged, and the gear for measuring capacitance cannot be used. The main reason may be that the voltage is wrongly measured when it is live, which leads to damage to the internal components of the multimeter
3. It is more common to select the wrong gear, or choose the wrong gear without paying attention, or the jack is not inserted correctly. But since the questioner came to ask the question, I think this article can be ignored.
The multimeter does not respond to the capacitance measurement. The reasons are: 1. Capacitor failure or open circuit; 2. The capacitance is too small; 3. The function of the multimeter to measure the capacitance is damaged or unavailable; 4. The measurement method is wrong.
The reason why the multimeter cannot measure the capacitance value
1. The multimeter and the capacitor have no capacity
First of all, it is necessary to rule out whether the multimeter is faulty, what about him? The method of multimeter failure is to use the multimeter to measure the resistance. If there is a standard resistance to measure the standard resistance, it may calibrate the electric barrier of the multimeter. If you have a response when Wang Yongmeter measures the resistance and the value is normal, then we can judge that the multimeter is not damaged.
The capacitor has no capacity, which cannot be observed by the naked eye. If we use a multimeter and there is no response, then we need to replace a new capacitor and use a multimeter to measure it. If the capacitor responds, then we can judge whether the previous capacitor did not respond. due to lack of capacity.
2. Not choosing the right gear
To measure capacitance, you can use the resistance file or the capacitance file. You can use the pointer multimeter or the digital multimeter. If you use the pointer multimeter, you must choose a good meter. It is more obvious when we observe the return to the center. If the capacitor has a large capacity and a large gear is selected, the fluctuation is relatively small, and sometimes we cannot detect it with the naked eye.
If we choose a digital multimeter, we must first find a good gear to observe the value change. Generally, when the capacitor is discharged, it will fluctuate, and then returning to the forest is only the discharge process, indicating that the capacitor is good.
3. Directly select the multimeter for measuring capacitance value
With the above experience, we can directly buy a multimeter that can measure the capacitance value, put the multimeter to the capacitance position, put the red test lead on one foot, and put the black test lead on the other foot. Generally, the capacitance of the multimeter has only one position. , directly connected for measurement, if the capacitance is good, the capacitance value can be displayed directly on the screen, and the measured value will have a 5% error of the calibration value.
