The Basic model WZ12A includes a soft-iron core and is used for general current measurement starting at 15 A. It demonstrates a traditional, cost-effective current transformer design with a transformation ratio of 1000:1.

All other WZ12 series clip-on current sensors are equipped with a top-quality metal core which reduces eddy-current loss and allows for accurate measuring results even with the low primary current.

Damping diodes integrated into the measurement output of the current transformers (with current output) protect the secondary side against overvoltages which occur if the measuring circuit is interrupted, or if the measuring instrument has not been connected.

This function is performed by internal load resistors for the current sensor models (with voltage output). Thanks to their compact design, these current clips easily fit into any service case or accessory compartment. Depending on the type, they are suitable for the measurement of motor current, for measurements at distributor terminals (WZ12A) or for the measurement of minimal to intermediate current (WZ12B) at machinery and current consumption at electronic devices, or the measurement of residual current as of 1 mA (WZ12C, Clip 0100S with selectable measuring ranges), right on up to measurements in systems with up to 240 A. Rugged mechanical construction and all requirements set forth by the latest international safety standards are taken into consideration in the design concept of the clip-on current transformers. WZ11 current clips are physically somewhat larger than WZ12 series devices, but they offer a larger spectrum of current measuring ranges and a higher voltage category.