Method for determining gas concentrations and gas sensor with a solid electrolyte

US5403452A · kind A · utility

Assignee

• Hartmann & Braun Aktiengesellschaft · DE

Inventors

• Bernd Hielscher · Bad Vilbel, DE
• Berthold K. P. Horn · Friedrichsdorf, DE
• Martin Schmah · Frankfurt, DE

Key dates

• Filing date: Sep 28, 1992
• Grant date: Apr 4, 1995
• Expiry date: Sep 28, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4045
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method for determining the concentration of gases in a mixture of gasses by means of a gas sensor composed of three electrodes 1,2,3 and a solid electrolyte 4 upon the surface of which are secured the electrodes. A voltage Us being composed of a dc component Udc and an ac component Uac is applied to at least two electrodes, the measuring electrode 1 and the counter electrode 2. Us is controlled with reference to the reference electrode 3. The voltage components Udc and Uac of the voltage Us are chosen so that the metal salt formed by the ions of the solid electrolyte 4 with the gaseous components to be detected is again decomposed. The ion, current flowing between the electrodes is measured in dependence upon the voltage as applied. The concentration of the several gasses can be determined by known mathematical methods from the functional relation between the ion current and the voltage Us.