When it comes to the tools used in electrical engineering, then many are used for testing and measuring. LCR meter is also one among those which is used to measure the inductance, capacitance, and resistance of an electronic component. The impedance is measured internally and is converted for a display to the corresponding capacitance or inductance value in more straightforward versions of this equipment.
Glossary and terms that one should know:
- Inductance (I)
- Capacitance (C)
- Resistance (R)
An LCR meter is an instrument that is used to measure all three that are inductance, resistance, and capacitance. Various manufacturers produce a wide variety of LCR meters, capacitance meters, and resistance meters when needed for the measurement of the high as well as low resistance. One can also find it easy to have a variety of resistance, capacitance, and inductance standards for all of the calibration needs.
Coming on the digital LCR meter, then it measures the current flowing through DUT that is the device under test and the voltage across DUT. It also measures the phase angle between the measured voltage and current, and then through these three measurements, all impedance parameters can be calculated. Kelvin connection, which a typical LCR meter has four in numbers which is used to connect the DUT, and this minimizes errors due to cabling and connection to the device under test.
Types of LCR meters
- Handheld: handheld DMM use the DC technique to measure the capacitance and is designed as DMM. Here the meters have the accuracy of +/-1%, and the measurement of capacitance is based upon measuring the RC time constant of DUT and calculating capacitance. Because these are lightweight, portable, and battery-operated, so these are more preferred.
- Benchtop LCR meter: here, you have more features as compared to the first one. Better measurement accuracy to0.01% and the programmable frequency are some of the better features that you can have in them. These are used for AC calibration of inductance, capacitance and resistance standards, production testing of components and sensors, and constant dielectric measurements with a variety of dielectric cells.
Use of LCR meter
- Test frequency: in electrical engineering, it is always needed to test the frequency, and the electrical components need to be screened at the frequency for which it is finalized for the utility. For measuring the frequency, the instrument which has a wide range of frequency and multiple programmable frequencies is needed. LCR meter with programmable frequency is more flexible.
- Test voltage: in the LCR meter, the AC output voltage can be programmed to select the signal level applied to the device under test. With the AC output, the source resistance is effectively connected in series. There is a voltage drop across the resistor; the voltage applied to the device depends on the value of the source resistor and the impedance value of the device.
- Speed/accuracy: The faster your measurement be, the less precision in the measurement is there, and the more accurate your measurement, the more time it takes. We can have three measurement speeds in the LCR meter, which are slow, medium, and fast. The choice is yours for the device under test.
