The output voltage of Rogowski coils is proportional to the derivative of the primary current. Therefore, an integrator circuit is needed to convert this signal so that it is proportional to the value of the primary current. This integrator is a fundamental component for measuring current with a Rogowski coil, and both the architecture and implementation of the amplification stage have a significant influence on the sensor's electrical performance, such as linearity, phase shift, and frequency bandwidth.
With a linearity error of less than 0.1% and featuring LEM's ART and ARU (coming soon) class 0.5 Rogowski coils, it offers a universal solution for meters and monitoring with exceptional measurement accuracy up to 5000 A.
The AI-PMUL integrator covers all necessary specifications with a single, universal product. Its simple configuration and clearly visible status on the front panel make setup easy. Adjusting the current range, input sensitivity, and output selection is done via a simple, reliable, and error-free system using ergonomic pushbuttons (x2) and visible bi-color LEDs, where green indicates the current range and red indicates the input sensitivity and output selection. Users can select from 12 current ranges from 100 A to 5000 A, 6 Rogowski coil sensitivity levels from 22.5 to 120 mV/kA, and 6 possible outputs (4 true RMS outputs: 0-20 mA, 4-20 mA, 0-5 V, and 0-10 V, and 2 instantaneous voltage outputs: 0-225 mV and 0-333 mV). A version with instant 1A output is also expected to be released soon.
The AI-PMUL, which operates at a temperature of -25°C to +70°C and runs on a single supply voltage of +24V, is supplied in a very compact size of 100x78x15 mm for mounting on a 35mm DIN rail.
For measuring low currents and under challenging conditions, an optional SMA coaxial input connector is available. Specifically, in three-phase systems, up to three AI-PMUL models can be stacked with an optional connector to share a single power supply.
The AI-PMUL series of integrators is CE marked and comes with a five-year warranty from LEM.
