Rogowski coils are toroidal air-cored sensors used to measure alternating current. They can be manufactured in several geometries—including full toroids, helical coils, and most importantly, PCB-based coils. Because they offer excellent flexibility, compact size, and broad customizability, Rogowski coils have become widely used in modern metering systems. They deliver strong performance in demanding environments, including high-voltage and high-current applications across wide frequency ranges.

Cost effective meters typically use shunt resistor for current sensing due to the straightforward working principle, low cost, and compact profile. Shunt resistors provide excellent linearity, fast response, and stable performance over a wide range of current levels. Shunt-based sensing enables accurate measurement without magnetic components, eliminating issues such as saturation and hysteresis commonly found in magnetic sensors.

Current transformers (CTs) offer high accuracy, excellent linearity, and reliable performance across a wide current and temperature ranges, making them preferred for precision metering applications. They provide galvanic isolation to protect electronic component, and have low power losses.