On the behavior of liquid/solid insulations at very low frequency

The apparent increase of the capacitance of solid/ liquid insulations measured at very law frequency under law voltage (∼1 volt), is mainly produced by the appearance of polarization layers (ions are impeded at the interfaces) provided that adequate conditions be fulfilled for the densities and mobilities of ions, and for the frequency and amplitude of the applied voltage. Thus, the insulation behaves approximately as a capacitance (the capacitance of the polarization layer, which may reach same) µF/cm², a value frequently encountered in Electrochemistry) in series with the resistance of the dielectric (which shunts the geometrical capacitance measured at high frequency).