Unlike the liner polarization technique or the electrochemical impedance spectroscopy (EIS), the electrochemical noise method (ENM) enables to measure the polarization resistance (
Rp) of an electrode under the conditions that are free from electrochemical perturbations caused by the application of current. However, as well as by the liner polarization, the measured
Rp by the ENM affected by solution resistance (
Rs) between the electrodes. Though this might produce a substantial error in the
Rp measured in lower conductivity solutions, the effect of
Rs on the
Rp has been scarcely investigated. In this study, the
Rp of a carbon steel electrode in dilute HCl solutions were measured by both the ENM and the EIS, under the same conditions. The error of the
Rp by the ENM was evaluated by comparing the
Rp by the EIS; the latter is regarded as free from the effect of
Rs. The
Rp by the ENM was higher than that by the EIS, and their differences were decreased with the concentration of the solution. However the degree of the differences was smaller than the
Rs measured by the EIS. This advantage would be brought by the specific electrode configuration used for the experiments.
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