Production and use of HV DC power cables cause formation of space charge within the insulating material and this can become a serious problem. One of the well known non-destrcutive techniques is the Pulsed Electro-acoustic(PEA). The method makes use of the acoustic wave generated by the charges existing in the sample under an applied pulse voltage and this wave is then detected by a piezo-electric transducer. Presently, construction of the improved Pulsed Electro-acoustic(PEA) system is capable of not only measuring space charge but also conduction current simultaneously on thin plaque specimens under a controlled temperature environment. This additional valuable piece of information enhances comprehension about their relationship. They complement each other to give details about charge carrier generation, transportation and accumulation. Such measurements allow insight into the charging processes taking place within the dielectric under study, and make it possible to select materials and interfaces which minimise the risk of breakdown in HV applications.