The PD LOC system solves the problem of precise positioning of partial discharge in hybrid cables (XLPE/PILC) and single core cables. During on-site testing, the exact position of the middle head is usually unclear, and it is also impossible to accurately locate the middle head through audio methods. The pulse generator of the system injects signals into the cable through an inductive coupler. The receiver includes an input amplifier for signal processing and a control unit. Display the distance of the transmitter through the partial discharge TDR function on the SX pulse transmitter menu.