An alternative to the use of a zero resistance ammeter for acquiring the current during electrochemical noise measurement has been presented. The method is based on the coupling of two nominally identical electrodes by a measuring resistor, and the potential across the measuring resistor can be used to calculate the coupling current. The physical implications of coupling two electrodes by a measuring resistor have been discussed, suggesting that the operation does not introduce a perturbation to the corrosion process perse. From the analysis of the relevant equivalent circuit, it has been pointed out that with the proposed method two values of apparent noise resistances can be obtained and the difference in such values, normalized by the value of the measuring resistor, provides an indication on the asymmetry of the electrodes. It has been shown mathematically that, for identical electrodes, it is possible to estimate the
electrode resistance based on the values of apparent noise resistance. The procedure has been experimentally validated and satisfactory agreement with the usual approach that relies on the use of a zero resistance ammeter was found. Importantly, the use of a measuring resistor instead of a zero-resistance ammeter eliminates the possibility that the noise produced by the active electronic within the measuring system is fed back to the corroding electrodes, thereby altering the corrosion process. Further, the proposed method has the advantage of enabling the calculation of a parameter S relating to electrode asymmetry. It has been demonstrated that values of S approaching 1 are a strong indication of electrode asymmetry; therefore, the reliability of the value of noise resistance should be questioned in such cases.