LCR Meters, also known as LCR bridges or LCR inductance meters, are electronic test equipment used to measure the inductance (L), capacitance (C) and resistance (R) of an electronic component.
When there is a change in the current flowing through a conductor, a corresponding change is induced in the voltage in it and in conductors surrounding it. This property is known as inductance. The ability of a body or a conductor to store electrical charge is known as capacitance. The opposition that a conductor offers to passing electric current through it is called resistance.
Most LCR meters use AC signals to measure the impedance of components. When using an LCR meter make sure you are using the correct settings as the wrong settings can cause poor measurement accuracy. Both analogue and digital LCR meters are available. The analogue is less expensive, and the digital variety is seen to be more accurate.
A digital LCR meter is used to measure the impedance flowing through a Device Under Test (DUT). It measures the voltage (V) across it, the current (I) flowing through it, and the phase angle between current and voltage. Subsequently, you can determine all the impedance parameters from these three factors.
Thus, an LCR meter measures the following parameters related to a circuit:
Handheld LCR meters: Small, lightweight and portable. They have multiple test frequencies and the data it captures can be transferred to a PC via a USB port. These LCR testers are typically digital, and used in field operations.
Benchtop LCR meters: Big and bulky. They can be operated on programmable frequencies and can be controlled via a computer. Benchtop LCR meters are able to measure higher maximum test frequencies, enabling a wider range of measurements. They also typically feature Kelvin connections (also known as four-terminal sensing) to minimise measurement errors caused by lead and contact resistances.
Bridge Method: This method is used for measuring frequencies below 100 kHz.
LCR Measurement by Current-Voltage Technique: Using this method, the LCR measurement of a component is done by measuring the current and voltage. Then the impedance values are found out from these two quantities.
While both LCR meters and multimeters are essential tools for electronic testing, they serve distinct purposes and offer varying levels of precision. Understanding their differences is crucial for selecting the right instrument for specific applications.
Primarily designed to measure inductance (L), capacitance (C), and resistance (R) with high accuracy. Utilises AC signals to determine impedance and provide detailed analysis of the components within an electrical current.
Use cases include:
Measures voltage (V), current (A), and resistance (R). Primarily used for troubleshooting, circuit testing, and general electrical measurements. Often include basic capacitance measurement capabilities, but lack the precision and frequency range of dedicated LCR meters.
Use cases include:
Yes, LCR meters are capable of measuring Equivalent Series Resistance (ESR), a vital parameter for capacitor analysis. ESR is the total resistance within a capacitor, accounting for factors like dielectric losses and lead resistance.
How LCR Meters Measure ESR:
While LCR meters can handle ESR, dedicated ESR meters might offer better accuracy and speed in some cases.
Limitations and Considerations of LCR Meters in ESR Measurement:
Best Practices for ESR Measurement Using LCR Meters:
When selecting an LCR tester, avoid these common pitfalls:
LCR meters play a crucial role across various industries, providing essential measurements for quality control, research, and development. Here are a few examples:
RS is a trusted supplier and distributor of high-quality LCR meters in Australia, catering to diverse measurement needs. We offer a comprehensive range of benchtop and handheld LCR meters, alongside complementary electronic component testers like Ohmmeters or ESD testers for all your electrical needs. Our catalogue features leading brands like Keysight Technologies, Peak Electronic Design, Aim-TTI, and many more.
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