Abstract: Quantitative determination of ozone contained in a fluid by an amperometric method comprises the steps of:(A) providing an amperometric cell having a sensing electrode, a counter electrode, an aqueous electrolyte in contact with the sensing electrode and the counter electrode, and a membrane that is substantially impermeable to the electrolyte but permeable to gaseous media including ozone and oxygen for containing the electrolyte within the cell and for separating it from the fluid maintained external to the cell;(B) providing in the aqueous electrolyte a redox catalyst for chemically transforming the ozone upon its permeation through the membrane into an intermediary electroactive species capable of generating upon reaction with the sensing electrode an indicative electric signal in proportion with a concentration of the ozone in the fluid;(C) applying a predetermined potential across the sensing electrode and the counter electrode;(D) measuring a cell current generated by reaction of the intermediary elect

Abstract: A method for determination of a first electroactive and normally gaseous species (EAGS) and a second EAGS in a fluid medium containing both EAGS; the medium is contacted with a first working electrode that is sensitive but to the first EAGS and generates a first amperometric signal that is indicative of the first EAGS concentration; the medium is also contacted with a second working electrode that is sensitive to both EAGS and produces a second amperometric signal that is indicative of the sum of both EAGS concentrations; the second EAGS concentration is calculated from the difference between the first and the second signal. For example, hydrogen can be measured in the presence of oxygen and this can be applied to monitor a fluid ambient or stream to prevent formation of explosive mixtures or corrosive conditions.

Abstract: Quantitative determination of ozone contained in a fluid by an amperometric method comprises the steps of:(A) providing an amperometric cell having a sensing electrode, a counter electrode, an aqueous electrolyte in contact with the sensing electrode and the counter electrode, and a membrane that is substantially impermeable to the electrolyte but permeable to gaseous media including ozone and oxygen for containing the electrolyte within the cell and for separating it from the fluid maintained external to the cell;(B) providing in the aqueous electrolyte a redox catalyst for chemically transforming the ozone upon its permeation through the membrane into an intermediary electroactive species capable of generating upon reaction with the sensing electrode an indicative electrical signal in proportion with a concentration of the ozone in the fluid;(C) applying a predetermined potential across the sensing electropde and the counter electrode;(D) measuring a cell current generated by reaction of the intermediary el

Abstract: A method for determination of a first electroactive and normally gaseous species (EAGS) and a second EAGS in a fluid medium containing both EAGS; the medium is contacted with a first working electrode that is sensitive but to the first EAGS and generates a first amperometric signal that is indicative of the first EAGS concentration; the medium is also contacted with a second working electrode that is sensitive to both EAGS and produces a second amperometric signal that is indicative of the sum of both EAGS concentrations; the second EAGS concentration is calculated from the difference between the first and the second signal. For example, hydrogen can be measured in the presence of oxygen and this can be applied to monitor a fluid ambient or stream to prevent formation of explosive mixtures or corrosive conditions.

Abstract: A method of regenerating a membrane-enclosed amperometric or Clark cell having an operative current range for electroanalytical operation limited by a maximum current density of typically not more than 100 .mu.A/cm.sup.2 at the working electrode by subjecting at least one of the probe electrode in contact with a regeneration electrolyte, while the membrane is removed, to a regeneration current for causing a current density in the range of from about 1 to about 1000 mA/cm.sup.2 which is substantially higher, e.g. by a factor of at least 10 and preferably at least 100, than the maximum current density in electroanalytical operation.