This paper represents an attempt to apply electrochemical noise analysis to monitor copper corrosion rates in solutions simulating near neutral or acidic industrial waters, containing chloride, sulphate and bicarbonate ions. The very low noise levels characterizing these systems make the evaluation of the noise resistance possible only with a four electrode arrangement, where the electrode couples used to detect the voltage and current fluctuations have different surface areas. This arrangement is probably a handicap to the evaluation of the polarization resistance values from noise resistance data. Cyclic voltammetries were carried out in order to investigate the nature of the corrosion products obtained in solutions with different pH.