**7. Parametric studies**

The measurements, which enable the analyses of the diagnostic parameters dependency on the test and the cable conditions, were accomplished under defined and monitored environmental conditions, at the network frequency of 50 Hz, at selective test voltages in the range from 0.4 *Un* to 2.2 *Un* and within a temperature range from 10°C to over 90°C. All measured values of the dissipation factor are presented in a normalized form of *<sup>n</sup>* tan tan , where *<sup>n</sup>* tan is the measured value on brand new (reference) cable at room temperature.
