Abstract
Current distributions in an electrolytic cell were measured with a simple method, in which the potential difference between two points in a solution was detected as an A. C. signal by rotating double probe electrodes. The current intensity and direction were obtained by measuring the amplitude of A. C. voltage and phase difference detected, and by comparing them with those at a reference point. For a copper(T) sulfate solution at 25°C, the output voltage (amplitude) was measured with a copper probe electrode and a platinized platinum electrode in the current density range of 0.1 to 50 mA cm-2. Results showed that for uniform distribution of force line, a linear relation between the output voltage and applied current density held (Fig.5). The data had a coefficient of variation of about 1%. The current direction measured had an angular error within 72°. For non-uniform current flow lines, i. e., diverging, converging and curving lines, measured current intensity and its direction were in agreement with calculated intensity and direction within an error of 5% and 76°, respectively, for the copper probe electrode at a rotating speed of 65Hz (Table 1). A gold probe electrode had a poor reproducibility due to the high impedance of the electrode surface. It was found that not only a copper electrode regarded as a practically reversible electrode but also platinized platinum and bright platinum probe can be used for copper (II) sulfate solutions. This method will offer a new approach to the measurement of current distributions in an electrolytic cell.
