The PD Loc partial discharge (PD) pinpointing system is used to precisely locate any identified PD weak spots during an off-line PD diagnosis. In most cases, exact joint positions or cable parts are unknown and can't be found using audio-frequency methods, but the PD LOC solves this problem, enabling joints and cable parts to be precisely found and replaced as part of a regular preventative maintenance program.

The PD LOC system solves the problem of pinpointing for a wide range and mix of cables (XLPE/PILC) and for PD in joints of single core cables using an impulse transmitter that uses a inductive coupler to inject a signal into the cable. The result is then sent to a receiving and evaluating unit consisting of an input amplifier for processing the signal and a control unit.