For the maintenance of facilities of the electrical energy technology there are several strategies (event-oriented, time-oriented and status- oriented). Because of different evaluation of all criterion in the electrical power network depending on the equipment, voltage level and significance you can find all strategies. The status of technical systems changes dependend on the operating time and the operating conditions. Therefore a continuous status diagnotics or such a diagnostics taking place in defined time intervals must be carried out again and again.
Therefore Technical Diagnostics (TD) is the science of the cognition of the status or condition of technical systems. TD has the aim to gain relevant information about this status, to derive criterion from this information to specifically influence the existing status with the aid of theses criterion. In addition future conditions should be predicted, to get assistance in reaching a decision for planning and timely intervention. This means the use of non-destructive investigation methods or destroying model study methods. A function of this aim is the selection of diagnosis principles with high expressiveness and their realization in device-technical solutions as well as the evaluation of these principles as the basis of finding decisions.