EVALUATION CRITERIA ABOUT PARASITICS IN IMPEDANCE MEASUREMENTS OF IONIC CONDUCTORS

Impedance spectrum measurements of a ceramic ionic conductor material constitute a well known method for the optimization of these materials. Today the most adopted method consists, essentially, in the vectorial comparison between two sinusoidal signals, one taken as reference, over a wide range of frequencies. In this work, after some considerations about practical electrical connections, an evaluation criterion to eliminate the so-called 'parasitic impedance', noticeable chiefly at high frequencies (10 kHz), is proposed. A method is also reported which permits the voltage at the extremes at the measuring cell to remain constant.