Rogowskikäämit
Rogowskikäämit are flexible, air‑core coils used to measure alternating current noninvasively by surrounding a conductor. The voltage induced in the coil is proportional to the time derivative of the current flowing through the conductor, so the coil itself does not provide the actual current waveform. To obtain the current, the coil’s output must be integrated with an external integrator or measurement instrument. Because there is no magnetic core, Rogowskikäämit do not saturate and offer a wide bandwidth, making them suitable for capturing fast transients.
Construction and operation hinge on geometry. A Rogowskikäämi is typically a flat or round, insulated conductor
Applications and limitations. Rogowskikäämit are widely used in power electronics, switchgear, high-current laboratories, and pulsed-current measurements
History. The Rogowski coil was developed by Walter Rogowski in the early 20th century and is named