| 摘要 |
PURPOSE:To prevent the change of output potential with the elapse of time to prolong the life of an internal electrode, by using one obtained by coating a silver-silver chloride wire with hydrophilic synthetic org. substance as the internal electrode. CONSTITUTION:For example, a lead wire 2 is provided to the cap 1 provided to the upper end of the support pipe 10 of a comparison electrode and connected to silver- silver chloride wire 4 through a connecting piece 3. As the wire 4, one having a coating film 5 formed by applying a solution of hydrophilic org. substance such as acetyl cellulose to the wire and drying the same is used. This coated wire 4 is immersed in a saturated KCl solution 6 being a concn. internal liquid injected from the replenishing orifice 12a provided to the upper side surface of the support pipe 10 while the space of the pipe 10 which an ion permeable membrane 9 is attached by a guide 11 is filled with a dilute KCl solution 7 from the orifice 12b provided to the central side surface of the pipe 10. A porous ceramic cock 8 enables the electrical continuity of the part having the dilute internal liqid 7 received therein and the part in which the conc. internal liquid 6. The film 5 prevents AgCl from precipitating in the liquid 6 from the wire and KCl and AgCl form a complex to prevent the internal electrode capacity of the wire 4. |
