Based on the theoretical analysis, the value of the measuring resistor, Rm, has no effect on the corrosion process and on the estimated value of noise resistance. In order to validate this conclusion, the experiment of Fig. 9 was performed. Specifically, a pair of nominally identical specimens was initially coupled by a 4.7kΩ resistor and their potential with respect to a saturated calomel electrode was recorded by using a NI-USB 6009 analog-to-digital converter. The electrochemical noise signal was recorded using in-house developed software, acquiring at 1023Hz segments of 1000 points at each iteration. Between iterations, the 1000 values acquired were averaged to obtain a single value of potential, subsequently saved to the file used for later processing. The final dataset comprised potential values spaced 1±0.05s in time. Under the assumption that the noise present above 1023Hz is negligible compared with the noise present below 0.5Hz, this procedure enables an accurate recording of the potential noise in the frequencies of interest, avoiding aliasing of frequencies between 0.5 and 1023Hz and minimizing the 50Hz interference from the mains supply.
