摘要 |
PURPOSE:To obtain a pH-measuring electrode with a metal oxide for enabling pH to be measured accurately without being affected by a coexisting substance as a pH-sensitive film. CONSTITUTION:An electrode-sensitive portion 24 consisting of a sensitive film support 21 in a specified shape and dimensions. a metal oxide film 22 which is formed on one surface of this sensitive film support for example by sputtering, and a porous insulation film 23 which is clad on an entire surface of this metal oxide film 22 by sputtering in a similar manner is fitted into a penetration hole which is formed on a bottom surface of a cylindrical support pipe 25 in a liquid-concentration state. The metal oxide film 22 which becomes a pH- sensitive film is positioned outside the support pipe 25 where its nearly half contacts a liquid whose pH is to be measured (a liquid to be measured). The porous insulation film 23 covering the metal oxide film 22 eliminates an interference substance and protects the pH-sensitive film. |