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Potentiometrischer Sensor zur kombinierten Bestimmung der Konzentration eines ersten und eines zweiten Gasbestandteils einer Gasprobe, insbesondere zur kombinierten Bestimmung von CO2 und O2, entsprechendes Bestimmungsverfahren und Verwendung derselben

Potentiometric sensor for the combined determination of the concentration of gas component of a gas sample, comprises a sodium ion-conducting, solid electrolyte, a measuring electrode, a reference electrode and a referencing electrode
 
: Belda, C.; Fritsch, M.; Kusnezoff, M.; Feller, C.; Kretzschmar, C.

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Frontpage ()

DE 102009031773 A: 20090626
DE 102009031773 A: 20090626
G01N0027
Deutsch
Patent, Elektronische Publikation
Fraunhofer IKTS ()

Abstract
(A1) Die vorliegende Erfindung bezieht sich auf einen potentiometrischen Sensor zur kombinierten Bestimmung der Konzentration eines ersten und eines zweiten Gasbestandteils einer in einen Messgasraum (1) einbringbaren oder dort vorhandenen Gasprobe (P), umfassend einen Kationen leitenden, insbesondere einen Gruppe-1-Kationen leitenden, insbesondere einen Na+-Ionen leitenden, Festelektrolyten (2), eine ein erstes, bezueglich des ersten und/oder des zweiten Gasbestandteils gassensitives Material aufweisende, in Gasverbindung mit dem Messgasraum bringbare und/oder stehende und mit dem Festelektrolyten in flaechigem Kontakt stehende Messelektrode (3), eine ein zweites, bezueglich des ersten und/oder des zweiten Gasbestandteils gassensitives Material aufweisende, in Gasverbindung mit dem Messgasraum bringbare und/oder stehende, mit dem Festelektrolyten in flaechigem Kontakt stehende und elektrisch von der Messelektrode isolierte Referenzelektrode (4), und eine mit dem Festelektrolyten (1) in flaechigem Kontakt stehende, von der Messelektrode und von der Referenzelektrode elektrisch isolierte und gegenueber dem Messgasraum gasdicht abschliessbare und/oder abgeschlossene Bezugselektrode (5).

 

WO 2010149153 A1 UPAB: 20110117 NOVELTY - The potentiometric sensor for the combined determination of the concentration of a first and a second gas component of a gas sample that is introduced into a measurement gas chamber (1), comprises a sodium ion (Na+)-conducting, solid electrolyte (2), a measuring electrode (3), which has a first material that is gas-sensitive with respect to the first and/or the second gas component and which is brought into or is in gas connection with the measurement gas chamber and which is in planar contact with the solid electrolyte, and a reference electrode (4). DETAILED DESCRIPTION - The potentiometric sensor for the combined determination of the concentration of a first and a second gas component of a gas sample that is introduced into a measurement gas chamber (1), comprises a sodium ion (Na+)-conducting, solid electrolyte (2), a measuring electrode (3), which has a first material that is gas-sensitive with respect to the first and/or the second gas component and which is brought into or is in gas connection with the measurement gas chamber and which is in planar contact with the solid electrolyte, a reference electrode (4), which has a second material that is gas-sensitive with respect to the first and/or the second gas component and which is brought into or is in gas connection with the measurement gas chamber and which is in planar contact with the solid electrolyte and which is electrically insulated from the measuring electrode, and a referencing electrode (5), which is in planar contact with the solid electrolyte and which is electrically insulated from the measuring electrode and from the reference electrode and which is sealed off in a gas-tight manner from the measurement gas chamber. The sensor is formed for the determination of potential difference such as potential difference between the measuring electrode and the reference electrode, the potential difference between the measuring electrode and the reference electrode and the potential difference between the reference electrode and referencing electrode. The potential difference is electrically connected at both electrodes and/or the sensor is formed so that the first potential difference depends on the partial pressure of the first gas component and the second gas component, the third potential difference depends on the partial pressure of the second gas component and the first gas component, and/or the second potential difference depends on the partial pressure of the first and the second gas component. The measuring electrode, the reference electrode and/or the referencing electrode comprises an electric conductive electrode lead by which the electric potential of the measuring-, reference- and/or referencing electrode is tapped. The electrode lead is formed as metal wire and/or as printed layer and/or has an electrode grid in the form of a printed, partially permeable layer containing gold or platinum. The first gas component consists of carbon dioxide and the second gas component consists of oxygen. The referencing electrode is gas-tightly sealable by a gas permeable layer against the measuring gas area. The gas permeable layer comprises a printed layer and/or a gas permeable is section wisely formed from material such as solid electrolyte. The reference electrode comprises a third material gas sensitive related to the first and/or the second gas component and is an electrode connected with the solid electrolyte. The sensor comprises a reference gas area gas-tightly separated from the measuring gas area and/or the reference gas area is separated from the measuring gas area, where the referencing electrode is brought in gas connection with the reference gas area and/or the referencing electrode has a material based on solid body reaction. The measuring gas area and the reference gas area are formed on two opposite sides of the solid electrolytes. The gas-tight separation of both gas areas is carried out by the solid electrolyte and/or by a gas sealing electrolytically connected with the solid electrolyte. The measuring electrode and the reference electrode are formed on a first surface of the solid electrolyte and the referencing electrode is formed on a second surface opposite to the first surface of the solid electrolyte. The solid electrolyte consists of oxides of sodium and aluminum (Na2O.nAl2O3), where n=5 to 11. The solid electrolyte is formed as printed layer on a substrate containing aluminum oxide and zirconium oxide and is formed as a mold body produced from starting powder by pressing and sintering of starting powder and/or as a cation-beta-aluminum oxide-diffusion layer formed over a solid body reaction with a cation in an aluminum oxide substrate. The first material and/or the third material has a pure or a mixed alkali- and/or earth alkali carbonate such as sodium carbonate with gold and/or platinum. The second material and/or the third material consist of a quantity of silica and sodium silicate with gold and/or platinum and/or a mixture of titanium dioxide and sodium titanium oxide with gold and/or platinum. The second material and/or the third material consist of nickel oxide-containing borate glass. The first material, the second material and/or the third material comprises alkali- and/or alkali-earth nitrates such as sodium nitrate with gold and/or platinum or alkali- and/or alkali-earth sulfate such as sodium sulfate with gold and/or platinum. The measuring electrode, the referencing electrode and/or the reference electrode has a screen-printed and/or ink-jet recording layer and/or is formed as a mold body produced by pressing and sintering of starting materials. The measuring electrode and/or the referencing electrode are formed as planar layer with a thickness of 20-100 mu m. An INDEPENDENT CLAIM is included for a method for the combined determination of the concentration of gas component of a gas sample. USE - Potentiometric sensor for the combined determination of the concentration of gas component of a gas sample useful for ambient air monitoring, in breathing gas analysis, in the area of protective technology or for oven regulations, for controlling and/or observation of exhaust gases, in motor management system and/or in process technology to the control and/or regulation of processes in automatic baking lines, bioreactors or incubators (claimed). ADVANTAGE - The potentiometric sensor ensures simple, efficient and combined determination of the concentration of gas component of a gas sample.

: http://publica.fraunhofer.de/dokumente/N-159187.html