Abstract: A method consists in measuring ac impedance spectrum using gold, platinum or carbon working ultramicroelectrodes (1). The direct current DC potential pulse which overlaps with alternating current AC signal of an amplitude in the range from 0.005 to 0.015 V and frequency in the range from 10−2 to 106, Hz is applied at the electrode. The value of said DC potential pulse for a process of copper electrorefining is in the range from −0.4 to −0.9 V in relation to a platinum reference electrode (2). Resistance values characteristic of a given electrolyte (E) are obtained from said AC impedance spectrum and compared with standard characteristic obtained by standard additions method. A measuring system consist of electrodes (1, 2, 3) placed inside a measuring cell (4) filled with flowing industrial electrolyte.

Abstract: The method consists in registering curves by cyclic voltammetry method in the range of copper ion concentration up to 20 g/l or alternately by chronoamperometric method in the range of concentration from 20 to 60 g/l. A platinum or gold microprobe of a diameter in the range from 1 to 50 um and a copper plate reference electrode are used. The value of current density read off from said curves is compared to the calibration curves previously determined by standard additions method. For high concentration in the range from 20 to 60 g/l the calibration curves obtained in the range of temperatures from 15 to 60° C. are registered.