What Is an LCR Meter? Types and Selection Criteria
An LCR meter is a measuring instrument that measures the inductance (L), capacitance (C) and resistance (R) of coils, capacitors and resistors at a chosen test frequency.
An LCR meter is a measuring instrument that measures the inductance (L), capacitance (C) and resistance (R) of coils, capacitors and resistors at a chosen test frequency. It applies a small AC test signal, measures the impedance and also calculates dissipation factor (D), quality factor (Q) and equivalent series resistance (ESR). It is used for incoming component inspection, board repair and coil winding; a capacitance meter is a simpler instrument that only measures capacitor capacitance.
Types of LCR and capacitance meter
| Type | What it measures | Example in the catalogue |
|---|---|---|
| Capacitance meter | Capacitor capacitance (and resistance), by range | UT601 |
| Ranged L/C/R meter | Inductance, capacitance and resistance, by selecting a range | UT603 |
| Handheld LCR meter | L, C, R plus D, Q, ESR; selectable test frequency | UT612, UT622A, UT622C, UT622E |
| Benchtop LCR meter | Wide frequency range, high accuracy, computer and sorting-line interfaces | UTR2810E, UTR2810E+, UTR2811E+, UTR2830E, UTR2832E |
Selection criteria
- Test frequency: Measure the component close to the frequency it will operate at. Mains rectifier electrolytics are measured at 100 Hz or 120 Hz, switched-mode supply coils and capacitors at 10–100 kHz.
- Measured parameters: Choose a model that also shows D, Q, ESR and phase angle. If you need the DC resistance (DCR) of a coil winding, check that the function is available.
- Basic accuracy: Benchtop models give higher accuracy. The names of the UTR2830E and UTR2832E in the catalogue state 0.05%, those of the UTR2810E+ and UTR2811E+ state 0.1%. Accuracy varies with frequency and the measured value.
- Series and parallel equivalent circuit: Low-impedance parts (high capacitance, low inductance) measure more accurately in series mode; high-impedance parts (low capacitance, high inductance) in parallel mode.
- Connection and zeroing: For low impedances, a four-terminal (Kelvin) connection reduces lead and contact resistance effects. Choose a model with open- and short-circuit zeroing.
- Handheld or benchtop: Handheld suits field work and repair; for pass/fail sorting and computer logging in production, choose a benchtop model with RS-232 and Handler.
Common mistakes
- Measuring the component in circuit: Parallel parts change the result; remove the component for an exact value.
- Connecting a capacitor without discharging it: A charged capacitor can damage the meter's input; discharge it safely first.
- Measuring small values without zeroing: At picofarad and microhenry level, the test leads' own capacitance and inductance add to the result.
- Measuring at the wrong frequency and assuming the capacitor is faulty: The capacitance of an electrolytic capacitor reads lower at high frequency. Compare at the data sheet frequency.
- Using a multimeter's capacitance range instead of an LCR meter: A multimeter does not give ESR or dissipation factor, and the test frequency cannot be selected.
LCR and capacitance meters in the catalogue
The LCR and Capacitance Meters category on Welibaba has 11 active products. All are Unit and priced on request:
| Model | Type | Test frequency |
|---|---|---|
| UT601 | Capacitance and resistance meter | By range, 200 pF–20 mF |
| UT603 | Ranged L/C/R meter | By range |
| UT612 | Handheld LCR meter | 100 Hz, 120 Hz, 1 kHz, 10 kHz, 100 kHz |
| UT622A | Handheld LCR meter | Up to 10 kHz |
| UT622C, UT622E | Handheld LCR meter | Up to 100 kHz (the UT622E also measures DCR) |
| UTR2810E, UTR2810E+, UTR2811E+ | Benchtop LCR meter | 100 Hz–10 kHz, 0.1% |
| UTR2830E | Benchtop LCR meter | 20 Hz–100 kHz, 0.05% |
| UTR2832E | Benchtop LCR meter | 20 Hz–200 kHz, 0.05% |
For voltage, current and general measurement see the digital multimeters category, and for resistance at milliohm level the micro-ohmmeters category.
Frequently asked questions
What is the difference between an LCR meter and a multimeter?
A multimeter only gives the capacitance value. An LCR meter lets you choose the test frequency and also measures inductance, ESR, dissipation factor and quality factor.
What is ESR and why is it measured?
ESR is the equivalent series resistance that represents a capacitor's internal losses. As an electrolytic capacitor ages its ESR rises even if capacitance looks unchanged, so it is among the first values checked in power supply faults.
Which test frequency should I choose?
Use the component's operating frequency: 100 Hz or 120 Hz suits electrolytic capacitors in mains filters; 10 kHz or 100 kHz suits small capacitors and switched-mode power supply components.
What do the D and Q values tell you?
D (dissipation factor) shows the loss in a capacitor, and Q (quality factor) shows how low the losses of a coil are. Q = 1/D; a small D is wanted in a capacitor and a large Q in a coil.