While exciting the Kelvin probe which

摘要

PROBLEM TO BE SOLVED: To make performable effective anti-corrosion measures about heat transfer tubes, waste water tanks, discharged water storage tanks, and the like.;SOLUTION: A Kelvin probe 2 is placed opposite to, but so as not to be in contact with, the surface of a metallic material covered with a thin water film w. A bias voltage Vbias is measured while the probe 2 is excited, thereby finding effective self-potential E'corr. equal to the bias voltage Vbias in absolute value but reverse thereto in polarity. The occurrence and growth of pitting corrosion is determined by comparing the self-potential E'corr. with pitting corrosion potential Vc. Since the self-potential E'corr. appropriately expresses the state of a metallic material corroded in an actual use environment, the occurrence and growth of a pitting corrosion can be suppressed by anti-corrosion measures that are employed when a sudden fall is detected in the self-potential E'corr..;COPYRIGHT: (C)2004,JPO