METHOD AND DEVICE FOR MEASURING CHROMIUM CONCENTRATION IN CHROMIUM CONTAINING ALLOY

摘要

PROBLEM TO BE SOLVED: To easily determine the chromium concentration in a chromium depletion layer by immersing a metallic electrode consisting of the material to be measured of the alloy containing chromium in the electrolytic solution, increasing the potential to the passive state, stepping the potential in the cathode direction, and measuring the secular change of the current after stepping. ;SOLUTION: The open circuit condition (the condition where the potential difference between a reference electrode and a metallic electrode is measured) is kept until the natural potential 12 is settled to the prescribed value. The signal is transmitted from a function generation part so that the potential of the metallic electrode is increased straight relative to the time in the anode direction, and a potential control part regulates the potential difference between the reference electrode and the metallic electrode so as to be equal to the value of the function signal by flowing the current between the metallic electrode and a counter electrode. The current is constantly measured during this time. When the potential of the metallic electrode returns to the potential 13, the potential is stepped to the step potential 14, and the secular change of the current in the step time 15 is measured. The minimum chromium concentration of the metallic electrode is obtained from the secular change of the current.;COPYRIGHT: (C)1998,JPO