PURPOSE: To obtain a compact multi-ion sensor, which can be manufactured in large quantity at a low cost and has the high measuring accuracy, by covering a plate material made of conductive material with polyvinyl chloride, and forming an ion sensitive film on the surface of a slice piece, which is sliced in the vertical direction of a major axis.
CONSTITUTION: Polyvinyl chloride 2 is formed so as to cover the surrounding part of a circular conductive plate material 1. The surface of the conductive material 1 is made to be chloride 4 by electrochemical treatment. A signal line 3 is connected to the surface at the opposite side of the chloride 4. Tetrahydrofuran or tetrohydrofuran, wherein ion-sensitive film material is dissolved, is dropped on the surface, on which the chloride 4 is formed. Thus, an ion sensitive film 5 is provided. Both the polyvinyl chloride 2 and the ion sensitive film 5 around the conductive plate material are dissolved into the tetrahydrofuran. Therefore, after the evapolation of the tetrahydrofuran, the unitary body is obtained, and the ion sensitive film 5 is strongly bonded to the conductive plate material 1 and the covering layer of the polychloride 2. Thus, the ion sensitive film 5 is not peeled away, and the stable potential can be obtained.
WATANABE YOSHIO
SHIBATA YASUHISA
