How to check the capacitor

Condensers are widely and versatile used inFirst of all, in electronics. Radio-technical and television equipment, radiolocation, telephony and telegraphy, automation and telemechanics, computing devices and electrical measuring instruments, laser technology - this is not a complete list of areas of their application. They are used by virtually all branches of the national economy.

It is understandable that such a wide applicationcapacitors determines the diversity of their species. Along with miniaturized capacitors, there are real giants weighing several tons. Their capacity can range from a fraction of the picofarad to hundreds of thousands of microfarads, and the working nominal voltage can be in the range of several volts to many hundreds of kilovolts.

In our time in every house there isall kinds of household appliances, and, consequently, capacitors. Unfortunately, they often fail for various reasons, so the question is how to test the capacitor with a multimeter, tester or ohmmeter.

In practice, more often than not,breakdown and partial loss of capacity. The reason for the breakdown is associated with a significant excess of the permissible operating voltage. Usually, external signs of breakdown can be seen on the body of the element - spots, blisters, cracks, etc.

How to test a capacitor with a multimeter

For electrical verification it will be usefuluniversal device - multimeter. Before checking the capacitor, it must be discharged. It is especially important to observe this, starting to check the polar capacitor, which is characterized by high capacitance and high operating voltage. Ignoring this rule will damage the measuring device. To discharge a low-voltage capacitor, it is sufficient to short-circuit its terminals, and to discharge a high-voltage capacitor, this must be done through a resistor with a resistance of up to 10 ohms to avoid a spark. At the same time, it is impossible to touch the terminals by hand, otherwise an unpleasant electric shock is ensured.

It is important to know exactly how to check the capacitor in a particular situation, because the methods of verification depend on many factors.

The easiest way to perform a multimeter test,with the function of measuring the capacitance, it is true, while not to forget about the need to observe polarity rules when working with polar capacitors.

Check the capacitors with a multimeter that does not havespecial function, it is possible in the resistance measurement mode. Switching the multimeter to this mode, you need to touch the probes of the capacitor leads and, after waiting a couple of seconds, check the instrument's readings. If an infinitely large resistance value appeared on the device - the capacitor is working, if the zero one is out of order. If the number on the display shows some intermediate value, the capacitor has a leak and loses part of the charge.

Thus, a multimeter without a validation functioncapacity allows you to determine only the qualitative characteristics of the capacitor, but at least it makes it possible to draw conclusions about the need to replace it.

However, this test leaves unanswered the followingThe question is how to check the capacitor for breaking the circuit. Damage of this kind can occur if the integrity of the dielectric inside the element is partially or completely impaired. Such a capacitor also shows infinite resistance, but it is impossible to rely on this indicator as a proof of its usability.

Knowing how to test the capacitor with a tester, you canAlso determine if its capacity corresponds to the specified tolerance limits. Knowledge of the real capacity is necessary to make a decision about its replacement or further use.