PURPOSE: To obtain an electrode for an ion sensor which prevents contact between a conductive member and the water or measuring liquid in an external thermostatic chamber, maintains electrical insulation and permits secure integral assembly of the electrode by forming the electrode in such a way that the side face at the end of the conductive member thereof is sealed directly or via other insulating material by the inside circumferential edge part of an insulating sleeve or the end of an insulating pipe.
CONSTITUTION: A base plate 1 formed of PVC having an insulating characteristic in a potassium ion selective electrode has a central hole 2 at the center and a silver cylinder 3 is fitted to the inside surface of the hole 2. A lead wire 4 is connected to the cylinder 3 and is extended to the outside. A potassium ion selective film 5 is coated on the inside surface of the cylinder 3. The film 5 is a plastic film consisting of a PVC resin which is a base material for the film, dioctyl adipate which is a plasticizer and valinomycin which is an ion selective material. Insulating pipes 6a, 6b forming an inflow port and an outflow port for a measuring liquid are securely fixed by a sleeve 7. The sleeve 7 prevents intrusion of water to the boundary between the plate 1 and the cylinder 3 and the boundary between the cylinder 3 and the film 5 cooperatively with the pipes 6a, 6b and a spacer 8.
KATAYAMA TETSUYA
KOYAMA MASAO
