TutorialsHow to Measure Capacitance with A Digital Multimeter

How to Measure Capacitance with A Digital Multimeter

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A digital multimeter is a versatile instrument if you want to measure different electrical properties. Apart from resistance, voltage, and current, it can also test capacitance. In fact, capacitance is one of the most significant tests any digital multimeter should be able to do. But before we get to how to test capacitance.

What Is Capacitance?

The capacitance of an electrical component or circuit is its ability to store energy. Capacitor machines collect and store electrical energy for utilization later. On a multimeter, you will see the symbol of capacitance denoted by –| (–.

So, testing for capacitance will be testing for a capacitor’s ability to store electric charge for every unit of voltage on its plates. But how do you test capacitance with a multimeter?

Testing Capacitance with A Digital Multimeter

You can test capacitance with a digital multimer by following the below simple steps

Step 1- Turn On The Dial Button

Look for the symbol for capacitance and turn the dial. If your multimeter has only one dial for the capacitance testing, then that means it will automatically range itself. If not, then you will have to set the range yourself.

Step 2 – Turn On Rel Mode

To reduce the effects from the test leads capacitance, tun on REL mode. This, however, isn’t in all multimeters. Press the button while holding the test leads separately. Doing this will help prevent the test probes’ capacitance from interfering with the final reading of capacitance.

Step 3 – Connect the Test Leads

Now connect the test leads to the circuit or components terminals. Make sure you identify the positive and negative terminals before inserting the probes. The (+) sign stands for the positive terminal, while the (-) sign stands for the negative terminal.

If any of the test leads is longer than the other one, the shorter one is negative. Most times, they will be colour-coded, meaning the red for the positive and the black for the negative.

Step 4 – Check The Voltage

Read the result of the voltage from the capacitor on the multimeter display, then use it to calculate capacitance. The formula for calculating capacitance from voltage is Q/V. Q represents the charge, while V stands for voltage.

The multimeter’s display will show the capacitance value if it falls within the measurement range you set. If this value is greater than the measuring range or the capacitor is defective, it will appear OL.

With that, you will have successfully tested capacitance. That wasn’t too hard, was it?

What Are Capacitors and What Do they Do?

The capacitor is a component that can store electric energy or charge. This capacity for it to store electrical energy is why it is called a capacitor. It acts in much the same way as a rechargeable battery. Capacitors can be either small or huge like the ones used in large industries. Whether large or small, however, they all do the same work, which is store charge. A capacitor consists of two or more metal plates with parallel conductivity. They are close but aren’t attached since they need to be electrically separate. Air or other strong insulators like ceramic, mica or waxed paper are a good option for that. Rubber and some liquid gel, as with electrolytic capacitors, can also do it. The Dielectric is the insulating layer between the plates of a capacitor. It is responsible for preventing DC current from flowing through the capacitor. That enables voltage to always be across the two capacitor plates.

What Else Can You Test with a Multimeter?

Multimeters are highly versatile devices and will typically test other electrical properties in addition to capacitance. Such tests are the three main, which are resistance, voltage, and current. Additionally, it can also test for continuity, frequency, and even temperature. Temperature, however, is the preserve of select multimeters. Most Fluke Multimeters would test the temperature, though. The more tests a multimeter can do, the higher its price. As an electrical expert, you should be worried about what HVAC Multimeter you can use in your gadgets.

What to Look for In a Multimeter

Apart from the ability to test for capacitance and various other electrical properties, there are other things you will need to look for in a multimeter. Versatility is just one thing to look for since you don’t want to end up with a multimeter that can only test capacitance. You should look for accuracy, a sturdy build, and a simplistic device that is easy to use. A sturdy build will ensure you own the multimeter for a long time. At the same time, the accuracy means you won’t have to keep doubting your results’ validity. While most multimeters are relatively affordable, those with premium features will come at eye-watering prices, even for a multimeter. That is why you need to consider the above actors when getting a multimeter.

Michal Pukala
Electronics and Telecommunications engineer with Electro-energetics Master degree graduation. Lightning designer experienced engineer. Currently working in IT industry.