PEM CWTUM-F Split-Core Rogowski Coil

PEMNew product —CWTUM-FFork-shaped Rogowski coil

To cope with increasingly complex measurement environments, how to accurately measure the complete signal is an issue that measurement equipment must now address. As a well-known manufacturer of Rogowski coils, PEM has developed a new Rogowski coil — the CWTUM-F. Unlike conventional toroidal Rogowski coils, the front-end coil section of this probe is fork-shaped; the overall probe appearance is shown in the figure below.

It is evident that the probe front end of this Rogowski coil differs from that of conventional Rogowski coils; conventional Rogowski coils are larger and are subject to greater interference in complex environments. The open-loop design of this Rogowski coil also differs from conventional Rogowski coils, as shown in the figure.

Although the design has changed, the specifications of this Rogowski coil, compared with the CWT series, retain PEM's traditional style and show little change. The coil is divided into two series, CWTUM-F and CWTUMHF-F; both series have a measurement range of 60 A–12 kA, a withstand voltage of 1.2 kV, a peak di/dt of up to 100 kA/µs, an operating temperature of −40 °C to 125 °C, a coil length of 55 mm, and a coil-to-integrator length of up to 1 m (customizable). The CWTUM-F series has a wire diameter of 1.2 mm and a bandwidth of 20 MHz; the CWTUMHF-F series has a wire diameter of 1.7 mm and a bandwidth of 30 MHz; the remaining specifications are essentially the same. The figure below compares the specifications of the two series.

The design of the front-end coil is the most distinctive feature of this Rogowski coil; the specific dimensions are shown in the figure below.

The application scenarios are wide-ranging: measuring switching current waveforms in power electronics, measuring large DC current ripple, and measuring high-frequency sinusoidal currents, pulsed currents, or transient currents within the power-line frequency in RF applications. Because of its compact front-end design, it can be used in many narrow spaces, and the fork-shaped open-loop design also provides considerable convenience for testing, especially for measurements in dense power-electronics circuit areas, such as MOSFET or IGBT devices, and in environments with packages as small as TO-220, D2PAK, and other SMT power devices.