Abstract: A Clark-type gas detection apparatus includes a sensor electrode and a reference electrode exposed to an aqueous electrolyte solution which is isolated from a liquid medium surrounding the apparatus by a semi-permeable membrane. A preferred reference electrode for use in Clark-type apparatus comprises silver/silver chloride. Through the addition of an effective amount of a sulphate-based co-electrolyte to an electrolyte solution having a relatively low chloride ion content, it is possible to obtain an electrolyte solution having an ionic conductivity comparable to that of chloride-based electrolyte solutions currently used in Clark-type sensors while retaining sufficient chloride ion to drive the oxidation reaction near the reference electrode. The relatively low chloride ion content of the electrolyte solution of the present invention tends to suppress the dissolution of silver chloride from the reference electrode, and, consequently, the deposition of silver on the indicating electrode.

Abstract: A microelectrode array for use in electroanalytical chemistry in measuring the electrical characteristics of a solution. A microdisk electrode array is formed by sealing a piece of minigrid into an electroinactive embedding material. One end of the embedding material is polished off to expose an array of microdisks which is defined by ends of the minigrid filaments.