| 摘要 |
PURPOSE:To measure corrosion resistance speedily and accurately by calculating electric double layer capacity from solution resistance obtained by impressing an AC voltage of specific frequency between metal to be measured which is dipped in an electrolyte solution and an electrode arranged opposite it and impedance measured from a current measured by impressing a low-frequency AC voltage. CONSTITUTION:An AC voltage outputted from an oscillator 11 is impressed to the sample metal 15 dipped in the electrolyte solution 14 and the electrode 16, and a potential difference signal measured by a voltage measuring instrument 17 is inputted to a calculator 21 through an AD converter 19. Further, the electric signal is converted by a current-voltage converter 22 into a voltage signal, which is inputted to the calculator 21 through a peak holder circuit 25 and an AD converter 26 to calculate the solution resistance value, which is inputted to a computing element 27. On the other hand, the low-frequency AC voltage from an oscillator 28 is impressed to the metal 15 and electrode 16 and output signals of the voltage measuring instrument 17 and converter 22 are inputted to a computing element 30 through an AD converter 29, sample and hold circuit, and AD converter 32; and Fourier transform as to those inputs is performed to calculate the impedance and the computing element 27 calculates the electric double layer capacity to calculate the corrosion resistance. |
