How to Test a Capacitor With a Multimeter?

Capacitors serve several crucial functions in the design of an electrical system’s circuitry.

Capacitors serve several purposes in a circuit, including decoupling, power storage, filtering, noise suppression, protecting microchips from overvoltage, and more.

Age, heat, high voltage, humidity, chemical contamination, and moisture are all potential threats to capacitors. To prevent electrical and electronic failures, every company owner should have access to a digital multimeter and learn to recognize the warning signs of a failing capacitor.

Understanding how to test a capacitor’s functionality is vital. Let’s delve into how a digital multimeter can offer a quick and precise assessment.

Capacitors may be visually inspected to see if they are functioning properly. A bloated or bulging top or bottom is a clear indicator of a defective capacitor.

Ensure there is no discoloration or damage to the capacitor and PCB by checking the housing. An electrolyte leak is another sign of a failing capacitor. 

What Exactly Is A Capacitor?

To put it simply, a capacitor is a type of electromechanical energy storage device. These play a variety of roles in electrical and electronic circuits. A capacitor may be charged by connecting it to another component in an electrical circuit. As soon as it is connected, electricity will begin to flow through the capacitor.

When the capacitor’s primary plate can no longer store the charge, the secondary plate allows the electricity to flow back into the circuit. Capacitors go through a cycle of charging and discharging.

How to Use an Ohmmeter or Multimeter to Test a Capacitor?

Leveraging a multimeter’s ohmmeter function is a dependable method to test a capacitor. By evaluating its resistance, we can determine the capacitor’s condition.

To do this check, we connect the ohmmeter’s probes to the capacitor’s terminals. Given that resistance is not polarized, it makes no difference which way up it is.

Using an Ohmmeter to Measure Capacitor Resistance

If the resistance across the capacitor is very little, or close to 0, then we know the capacitor is broken. It seems to be giving the same result as if there were a short circuit across it.

A faulty capacitor might be indicated by a reading of very high resistance across it. There appears to be an open circuit across the capacitor, according to the readout.

A typical capacitor’s resistance would fall between these two values, maybe in the tens to hundreds of thousands of ohms range. But not 0Ω or several MΩ.

This is a quick and easy way to determine if a capacitor is faulty.

Capacitor Testing Requires A Multimeter Set To The Capacitance Setting.

If your multimeter also has a capacitance meter, you may use it to verify the capacitor’s capacitance. Just connect the multimeter’s probes to the capacitor’s terminals and read the outside capacitance markings. There is no significance to the polarity.

The configuration is identical to that used in the previous example; the only difference is that the multimeter has been switched to the capacitance setting.

The figure you get should be close to the capacitor’s rated capacitance. It’s possible that the actual measured capacitance will be slightly lower than the rated amount due to tolerance and the fact that (in the case of electrolytic capacitors) they can dry out with time. All OK, this works out nicely. Even if it’s a bit lower, it’s still a decent capacitor. If, on the other hand, you detect no capacitance or a much smaller value, the capacitor is broken and has to be replaced.

Testing the capacitance of a capacitor is a reliable way to assess its quality.

Measure the Voltage of a Capacitor

Performing a voltage test provides a straightforward approach to ascertain a capacitor’s health, offering clear insights into its operational status.

Capacitors serve as storage devices, after all. They can store voltages in the form of a potential difference between charges across their plate. There is a positive voltage at the anode and a negative voltage at the cathode..

Voltage between the terminals of a charged capacitor can be read to verify proper operation. If the voltage between the capacitor’s terminals remains at the level you charged it to, the capacitor is functioning as intended. Capacitor failure to charge and register voltage indicates faulty component.

Put A Capacitor On Charge

Applying direct current (DC) voltage to the capacitor’s leads will charge it. For polarized capacitors, the polarity is crucial (electrolytic capacitors). When working with a polarized capacitor, it is crucial to pay attention to the proper lead orientation and polarity.

The capacitor’s positive (or active) voltage is connected to its anode (the longer lead), while the negative (or ground) is connected to its cathode (the shorter lead). If you want to test a capacitor, you need to provide a voltage that is lower than the capacitor’s rated voltage for a short period of time. To illustrate, consider providing 9 volts to a 25 volt capacitor and allowing it to charge for a few seconds at this voltage. 

It will charge in a matter of seconds provided that you are not using an extremely large capacitor. At the end of the charging process, remove the capacitor from the power supply and check its voltage using a multimeter. At first, the voltage should be close to 9 volts (or the voltage you provided it).

Please take into account that when the capacitor’s voltage is discharged through the multimeter, the reading will quickly decrease and eventually reach 0V. However, the charged voltage value is what you want to see initially, as it will swiftly decrease afterward. A good and healthy capacitor will exhibit behavior like this. It’s broken and has to be changed if it loses electricity too quickly.

Useful Information 

It is also possible to measure the time required for a capacitor to discharge to a level that is about 36.8 percent of the peak value of the applied voltage. In the formula, the discharge time can be substituted for the capacitor’s actual value.

Capacitor testing, in short, is not a very difficult task. And a capacitor’s ability to store energy gradually declines with age. Consequently, it is preferable to regularly inspect radio components in electrical equipment, assuring their dependable and high-quality performance for many years.

Explore our wide range of multimeters and RLC meters available in our web store. Our technical support team is ready to guide you in choosing the right testing mode and addressing any questions you have about the process.

Conclusion

Every company should have access to a digital multimeter and learn to recognize the warning signs of a failing capacitor. Capacitors are electromechanical energy storage devices that play a variety of roles in electrical and electronic circuits. Age, heat, high voltage, humidity, chemical contamination, and moisture are all potential threats to capacitors. Capacitors are storage devices that store voltages in the form of potential difference between charges across their plate. Capacitor failure to charge and register voltage indicates faulty component.

Testing the capacitance of a capacitor is a reliable way to assess its quality. It’s possible that the actual measured capacitance will be slightly lower than the rated amount due to tolerance and drying out. Capacitor testing, in short, is not a very difficult task. If you want to test a capacitor, you need to provide a voltage that is lower than the capacitor’s rated voltage. A good and healthy capacitor will exhibit behavior like this. It’s broken and has to be changed if it loses electricity too quickly.

Content Summary: 

• Capacitors serve several crucial functions in the design of an electrical system’s circuitry.
• Capacitors serve several purposes in a circuit, including decoupling, power storage, filtering, noise suppression, protecting microchips from overvoltage, and more.
• Age, heat, high voltage, humidity, chemical contamination, and moisture are all potential threats to capacitors.
• To prevent electrical and electronic failures, every company owner should have access to a digital multimeter and learn to recognize the warning signs of a failing capacitor.
• The question is, how do you test a capacitor to see if it is functioning properly or broken?
• When using a digital multimeter, how can you quickly and accurately check the capacitor?
• Capacitors may be visually inspected to see if they are functioning properly.
• A bloated or bulging top or bottom is a clear indicator of a defective capacitor.
• Ensure there is no discoloration or damage to the capacitor and PCB by checking the housing.
• An electrolyte leak is another sign of a failing capacitor.
• To put it simply, a capacitor is a type of electromechanical energy storage device.
• These play a variety of roles in electrical and electronic circuits.
• A capacitor may be charged by connecting it to another component in an electrical circuit.
• As soon as it is connected, electricity will begin to flow through the capacitor.
• When the capacitor’s primary plate can no longer store the charge, the secondary plate allows the electricity to flow back into the circuit.
• Capacitors go through a cycle of charging and discharging.
• One reliable way to test a capacitor is to use the ohmmeter function of a multimeter.
• Checking the capacitor’s resistance will tell us if it’s in working order.
• To do this check, we connect the ohmmeter’s probes to the capacitor’s terminals.
• Given that resistance is not polarized, it makes no difference which way up it is.
• A typical capacitor’s resistance would fall between these two values, maybe in the tens to hundreds of thousands of ohms range.
• But not 0Ω or several MΩ.
• This is a quick and easy way to determine if a capacitor is faulty.
• If your multimeter also has a capacitance meter, you may use it to verify the capacitor’s capacitance.
• Just connect the multimeter’s probes to the capacitor’s terminals and read the outside capacitance markings.
• There is no significance to the polarity.
• The configuration is identical to that used in the previous example; the only difference is that the multimeter has been switched to the capacitance setting.
• The figure you get should be close to the capacitor’s rated capacitance.
• It’s possible that the actual measured capacitance will be slightly lower than the rated amount due to tolerance and the fact that (in the case of electrolytic capacitors) they can dry out with time.
• All OK, this works out nicely.
• Even if it’s a bit lower, it’s still a decent capacitor.
• If, on the other hand, you detect no capacitance or a much smaller value, the capacitor is broken and has to be replaced.
• Testing the capacitance of a capacitor is a reliable way to assess its quality.
• There is also the possibility of doing a voltage test to determine the health of a capacitor.
• Capacitors serve as storage devices, after all.
• They can store voltages in the form of a potential difference between charges across their plate.
• There is a positive voltage at the anode and a negative voltage at the cathode.. Voltage between the terminals of a charged capacitor can be read to verify proper operation.
• If the voltage between the capacitor’s terminals remains at the level you charged it to, the capacitor is functioning as intended.
• Capacitor failure to charge and register voltage indicates faulty component.
• Applying direct current (DC) voltage to the capacitor’s leads will charge it.
• If you want to test a capacitor, you need to provide a voltage that is lower than the capacitor’s rated voltage for a short period of time.
• To illustrate, consider providing 9 volts to a 25 volt capacitor and allowing it to charge for a few seconds at this voltage.
•  It will charge in a matter of seconds provided that you are not using an extremely large capacitor.
• At the end of the charging process, remove the capacitor from the power supply and check its voltage using a multimeter.
• At first, the voltage should be close to 9 volts (or the voltage you provided it).
• Please take into account that when the capacitor’s voltage is discharged through the multimeter, the reading will quickly decrease and eventually reach 0V. However, the charged voltage value is what you want to see initially, as it will swiftly decrease afterward.
• A good and healthy capacitor will exhibit behavior like this.
• It’s broken and has to be changed if it loses electricity too quickly.
• Useful Information  It is also possible to measure the time required for a capacitor to discharge to a level that is about 36.8 percent of the peak value of the applied voltage.
• In the formula, the discharge time can be substituted for the capacitor’s actual value.
• Capacitor testing, in short, is not a very difficult task.
• And a capacitor’s ability to store energy gradually declines with age.
• Consequently, it is preferable to regularly inspect radio components in electrical equipment, assuring their dependable and high-quality performance for many years.
• For that purpose, we have a variety of multimeters and RLC meters on our web store.
• Contact our technical support staff and we will be happy to assist you with selecting the appropriate testing mode and answering any other concerns you may have about the procedure.