HOW TO MEASURE CERAMIC CAPACITORS?

How to Measure Ceramic Capacitors?

How to Measure Ceramic Capacitors?

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In electronic circuit design, maintenance and troubleshooting, accurate measurement of ceramic capacitor parameters is one of the key steps. The capacitance, leakage current, equivalent series resistance (ESR), and dielectric loss factor (DF) of ceramic capacitors directly affect the overall performance of a circuit. Failure to accurately measure these parameters may result in poor capacitor performance, which may cause circuit failure or reduce efficiency. Therefore, this article will introduce several quick-to-follow practical methods to help readers measure and evaluate the parameters of ceramic capacitors. Many distributors offer a wide range of components of ceramic capacitor to cater to diverse application needs, like BTS117

Basic Measurement Tools


Digital Multimeter Most digital multimeters have a capacitance measurement feature, especially the multifunction models. They are generally easy to use and portable. However, the capacitance measurement accuracy of digital multimeters is relatively low, and they are usually unable to measure small capacitances or meet high-precision requirements.

Capacitance Meter Capacitance meters can measure capacitance values ranging from picofarads to farads and usually provide higher accuracy than standard multimeters. However, they are limited to measuring capacitance only, making them somewhat single-purpose.

LCR Meter LCR meters can measure inductance (L), capacitance (C), and resistance (R), and they are often capable of measuring equivalent series resistance (ESR) and dissipation factor (DF), making them suitable for more precise measurements.

Measuring Capacitance Values



  1. Measuring a Digital Multimeter


Set the multimeter to the capacitance measurement mode (usually indicated by “C” or the capacitance symbol) and connect both ends of the capacitor to the measurement probe of the multimeter. If it is polarized (e.g. electrolytic capacitor), take care to connect the positive probe of the multimeter to the positive terminal of the capacitor.

Read the capacitance value on the display. Multimeters are usually suitable for measuring capacitance values in the microfarad to millifarad range.

  1. Using a capacitance tester or LCR meter


Turn on the capacitance tester or LCR meter and select the capacitance measurement mode. Select the appropriate test frequency according to the type of capacitor, usually 1 kHz or 100 Hz. Connect both ends of the capacitor to the test meter. The LCR meter usually also provides other parameters such as Equivalent Series Resistance (ESR) or Loss Factor (DF). Read the measured values and select the appropriate range according to the parameters of the device.

Measuring Leakage Current



  1. Using a High Resistance Meter


Set the Hi-Resistance Meter to the appropriate range and connect the probes of the Hi-Resistance Meter to both ends of the capacitor. The Hi-Resistance Meter will directly display the leakage current value of the capacitor. Record the measurement results and compare with the standard reference value.

  1. Using a Power Supply and Multimeter Combination


Select the appropriate supply voltage and connect the positive terminal of the power supply to the positive end of the capacitor and the negative terminal to the positive pen of the multimeter. Set the multimeter to the current measurement mode and connect the negative pen to the negative terminal of the capacitor. Turn on the power and observe the current reading of the multimeter. There may be a large charging current at the beginning, waiting for the current to drop and stabilize, the stabilized current is the leakage current.

Measuring Equivalent Series Resistance (ESR)



  1. Using the ESR Tester


Turn the ESR tester on and select the appropriate range. Connect the tester probe to the pins of the capacitor and read the ESR value displayed on the tester. Most ESR testers will output a specific frequency during the measurement to make the results more closely match the actual application conditions.

  1. Using the LCR Meter


Set the LCR meter to ESR measurement mode. ESR measurement options can usually be found in the Inductance, Capacitance and Resistance measurement modes. Select the measurement frequency, usually 100kHz or 1kHz, and connect the probe of the LCR meter to both ends of the capacitor. Read the ESR value on the LCR meter screen and record it.

Measuring Dielectric Loss Factor (DF)


Measuring the DF value with an LCR meter

Set the LCR meter to “DF” or “D” measurement mode. Select the appropriate test frequency according to the application environment and rated frequency of the capacitor. Connect the test probes of the LCR meter to the two pins of the capacitor. Read the DF value displayed on the screen and record it.

Measuring Capacitors in Circuits


In practical applications, capacitors on circuit boards are sometimes not easily removable, so capacitance values must be measured directly in the circuit. Some high-end LCR meters allow direct measurement of capacitors under certain conditions. To confirm the health of a capacitor, you can check for leakage currents, high Equivalent Series Resistance (ESR) and other problems. For example, capacitor failures are often signaled by a significant drop in capacity, an increase in leakage current, or an abnormal ESR value.

Because measuring capacitors in a circuit can be affected by neighboring components, some error exists in the measurement results. In order to minimize the error, it can be corrected by the following methods: First, make sure that the capacitor is completely discharged before measurement. Second, use an LCR meter with an "auto-calibration" function, which can minimize the deviation caused by the stray capacitance of the measurement line. Finally, compare the measurement results with the standard parameters of a new capacitor of the same model by means of a comparison test.

 

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