Inductors are commonly used in electronic and electrical circuits in a wide range of industrial and scientific instruments and applications. Inductance is the ratio of the voltage change across an inductor to changes in current and measures the amount of magnetic energy that can be stored in the inductor. Typically, coils of wire are used as inductors due to their increased effect of the magnetic field generated through the inductor.
Inductance measurements depend on a number of factors. The material characteristics of the core, size and shape of the coil windings, the number of turns of the coil, and material immediately surrounding the coil can all affect the measured inductance.
There are two ways in which inductance is used in electronic circuits. Mutual inductance is when a circuit voltage is developed as the result of a change in current in a different circuit due to the magnetic field that links both circuits, such as in transformers. Self-inductance is when the voltage in the coil changes as a result of a change in its own current due to the magnetic effect caused by the current flow.
One of the most common uses of inductance is the inductive loop detectors placed at some traffic intersections. A loop of energized wire is placed just below the pavement of the road and when the metal of a vehicle passes over the loop, it changes the inductance of the magnetic field, which is used to activate the traffic signals. A variation of the inductive loop is also used in metal detectors to detect metals as the loop is passed over them.
An LCR Meter is a specialized type of electronic test equipment used to measure the capacitance, resistance, and inductance of electronic components or other devices. LCR Meters measure a number of characteristics of the components and from these measurements, all impedance parameters can be calculated. LCR Meters can be purchased in either benchtop or handheld units.
Most standard Digital Multimeters do not measure inductance. Inductance measurement requires advanced circuitry and the simple act of measuring the inductor can cause self-inductance and give inaccurate readings. Standard Digital Multimeters that measure inductance would have lower accuracies and would not be suited for most laboratory applications.
Best LCR Benchtop Meters
Benchtop LCR Meters offer more advanced features than handheld meters and have accuracies as high as ±0.02%. These meters are typically used in calibration or inspection laboratories.
The IET Labs Quadtech Precision LCR Meters are IET’s newest LCR Meters and have a base measurement accuracy of 0.05 to 0.1 %. IET labs purchased and maintains the GENRAD 1600 Series of LCR ‘Digibridge’ Meters that have been the industry standard for over 50 years. The base accuracy for these units is as low as ±0.02%.
BK Precision manufactures a number of quality benchtop LCR Meters. Their Model 891 and 894 Benchtop LCR Meters are versatile meters capable of measuring inductors to an accuracy of ±0.05% at a wide range of frequencies. The Model 889B LCR/ESR Meter has a basic accuracy of ±0.1% and also has many functions of standard Digital Multimeters to accurately measure DC/AC voltage and current, resistance and continuity.
The Keysight E4980AL Precision LCR Meter is an industry standard LCR Meter that provides the best combination of accuracy, speed, and versatility. They are ±0.05% basic accuracy with superior measurement repeatability.
The GW Instek LCR-6000 series High Precision LCR Meters have an abundance of features. With a ±0.05% basic accuracy, it is an excellent tool for R&D, production, or inspection testing.
Best LCR Handheld Meters
Handheld LCR Meters are lightweight, portable and battery operated and are easy to use for on-site or other mobile applications. Generally, meters in this class have an accuracy of ±0.5% or better.
The Keysight U1700 Series Handheld LCR Meters allow the performance of basic inductance measurements at an accuracy of ±0.2%. They have the capabilities to measure at higher frequencies typically found only in benchtop meters.
The BK Precision Models 878B, 879B, and 880 Handheld LCR Meters are cost-effective meters to measure inductance quickly and accurately. The Model 880 offers advanced capabilities such as a 4-terminal configuration, basic measurement accuracy up to ±0.1% and selectable test frequencies.
If you have any questions or need advice on Inductance measuring equipment, contact us at e2b calibration.