| 摘要 |
PURPOSE:To localize the flowing current distribution within a pitting and know the corrosion speed or polarization resistance thereof to detect a local corrosion progressing under the probe, by constituting a probe of special shape by some electrodes. CONSTITUTION:The surface area of an insoluble opposed electrode 2 is required to be larger than at least that of a pitting or the like to be measured. It is desirable to select the surface area of the paired electrode to be not smaller than 10cm<2>, since a pitting to be measured has a maximum diameter of about 3cm. A paired electrode chamber 3 in an electrical insulator container 1 is desirably a container having a volume not smaller than 60ml. A minute bore 4 is provided in the wall surface of the container corresponding to the paired electrode. Reducing the minute bore 4 in diameter makes it possible to obtain an excellent resolving power. The diameter is preferably 0.05-1mm. in consideration of practicality. For a reference electrode 7, any material can be employed, provided that it is stable in seawater and other environment. Carrying out a corrosion speed monitoring according to the polarization resistance method by the use of this probe makes it possible to directly detect a pitting in a structure corroded in seawater or other liquid. |
