LCR Meters are a type of 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 the passage of 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 result in poor measurement accuracy. Both analogue and digital LCR meters are available. The analogue are less expensive and the digital variety are seen to be more accurate.
Uses of an LCR Meter
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:
● dissipation factor
● quality factor
● phase angle between the current and voltage
Types of LCR Meters
Handheld LCR meters: Small, lightweight and portable. They have multiple test frequency and the data it captures can be transferred to a PC via a USB port. Typically used in field operations.
Benchtop LCR meters: Big and bulky. They can be operated on programmable frequencies and can be controlled via a computer.
Techniques used with LCR Meters
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.