Bruit electrique dans les electrolytes 1.1 aqueux - 2. Cas des fortes concentrations - bruit d'interface

The conductivity of concentrated aqueous solution of KCl (10^?2 to 2 molar) has been measured in terms of electrical noise voltages. Under conditions of thermodynamic equilibrium, the liquid produces pure white noise; while there may arise a potential difference between the two electrodes while measuring noise voltages, there is no net current flow since there is no electrochemical reaction to supply the energy required for a non-zero mean current. A noise spectrograph has been developed which allows the measurement of very low values of equivalent noise resistance using a cross correlation method. The evaluation of the results is automated by means of a multiprogrammer coupled to a computer. Noise produced at the electrode interfaces is independent of the electrolyte concentration. Deducting the interfacial noise component from the total noise product by the cell allowed the evaluation of the equivalent noise conductivity of the electrolyte. Up to 1 molar concentration, the resulting values agree well with tabulated values within the errors of the measurements.