| 摘要 |
PURPOSE:To extend the life of a Cl<-> ion selective electrode which is silver/silver chloride electrode even if the silver chloride does not exist in a measuring liquid by providing a sacrificial electrode consisting of the material equal to the material of a sensitive body to be deposited on the ion selective electrode on the inside surface of a cylinder in a space flow part. CONSTITUTION:The sacrificial silver/silver chloride electrode 8 is formed on each inside surface of the spacers 3 between the Na<+> ion selective electrode 4 and the K<+> ion selective electrode 5 and between the electrode 5 and the Cl<-> ion selective electrode 6 and further a silver chloride layer 9 is provided to the inside surface. The components of the silver/silver chloride electrode deposited on the electrode 8 on the surface of the flow passage for the liquid to be measured are dissolved to increase the concn. of AgCl in the fluid. The deterioration with lapse of time is thus decreased and the stable measurement is made possible. More specifically, the AgCl elutes from the electrode 8 existing on the upper stream of the electrode 6 in the stage of conducting the liquid to be measured, etc. to the ion sensor body 20 and measuring the same and therefore the concn. of the AgCl in the measuring liquid is increased and the dissolution of the AgCl from the electrode 6 is suppressed. The extention of the electrode 6 life is thus made possible. |
