“…However, the EaB measurement is a commonly used method to determine the degradation of polymers [ 24 , 25 ]. However, the EaB test is naturally destructive, and it requires samples removal; thus, it is not practical for on-site testing [ 2 , 5 , 10 , 26 ]. Therefore, non-destructive electrical-based condition monitoring techniques have been the focus of scientific interest, such as dielectric spectroscopy, return voltage measurement, and the polarization-depolarization current method [ 8 , 9 , 10 , 14 , 15 , 19 , 20 , 26 , 27 , 28 , 29 , 30 ].…”