This article explores the measurement of electric current using optical fibers, primarily through the Faraday effect, also known as the magneto-optic effect. Fiber-Optic Current Sensors (FOCS) offer high accuracy, modularity, and easy installation. The FOCS can measure uni- or bi-directional DC currents up to 600 kA. The FOCS Series Fiber Optical Current Sensors are passive, all-dielectric devices designed for precise current measurement without metal components, making them immune to electromagnetic interference noise. The result is exceptional accuracy and reliability. Based on the magneto-optic effect, FOCS. An electromagnetic instrument transformer is a common device used to measure large current values in high-voltage electrical networks; it has been in use for more than a century.
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