ELECTROCHEMICAL MEASURING SENSOR AND DIAGNOSING METHOD OF CORROSION RESISTING FUNCTION OF COATING FILM

摘要

PURPOSE:To enlarge the application range of a sensor to a coating film of high impedance, and to secure the stability of a contact area, by inserting a pair of electrodes or a reference electrode within said sensor and at the same time filling macromolecules of high water absorbing power therein, and covering an opening portion with fibers. CONSTITUTION:Within a sensor 15 employing macromolecules 1 of high water absorbing power, there is inserted a pair of electrodes or a reference electrode 2 depending on the kind of measurement. Macromolecules 1 of high water absorbing power which absorb an electrolyte are filled in a chamber of the macromolecules. The area and shape of an object to be measured are restricted by an opening portion 7 which is covered with fibers 3 withstanding the expansion pressure of the macromolecules 1 and not allowing the macromolecules 1 to pass through. Therefore, the wettability of an interface with the object is controlled by the characteristic of the macromolecules 1, enabling the measurement under stable conditions, with a constant mass ratio of the macromolecules 1 and the electrolyte. Moreover, no bubbles are left owing to the expansion pressure of the macromolecules 1, and it becomes possible to measure a coating film of a high impedance. In addition, since the macromolecules 1 keep the electrolyte for a long time, a supplementing device of the electrolyte is not required.