Patent EP0172746A2 successfully refreshed from Google Patents.
EP0172746A2
Expired / Lapsed
EP
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Electrochemical device
Assignee: NGK Insulators Ltd
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Filing: 1985-08-19
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Granted: —
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Expires: 2005-08-19
Abstract
Abstract 57 An electrochemical device for measuring oxygen partial pressure of a measurement gas has a sensing cell which comprises a first planar solid electrolyte body 4, a first and a second porous ele6trode 20, 22 on the first electrolyte body, the second electrode being exposed to a reference gas, and a member 2 which has a predetermined diffusion resistance to a measurement gas and covers the first electrode. An electric current is applied between the first and second electrodes, to induce an electrode reaction to control the atmosphere adjacent to the first electrode. To make the device capable of measuring not only oxygen partial pressure of lean-burned exhaust gas but also the amount of unburned components in a rich-burned exhaust gas, the device has a pumping cell which comprises a second planar solid electrolyte body 8, and a third and a fourth electrode 24, 26 of porous structure on the second electrolyte body. The third electrode is exposed to the said reference gas and the fourth electrode is exposed to the measurement gas. An electric current is applied to flow from the third electrode to the fourth electrode, whereby an oxygen component of the measurement gas is moved into the reference gas.
Inventors
- 👤 Kazuyoshi Shibata
- 👤 Yoshihiko Mizutani
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 18:28
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/407; G01N27/4071; G01N27/4065; G01N27/416; G01N27/417
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
274 words
An electrochemical device having an electrochemical sensing cell which includes: a first planar oxygen-ion conductive solid electrolyte body; a first and a second electrode of porous structure disposed on the first planar solid electrolyte body such that the first and second electrodes are spaced from each other; diffusion resistance means which has a predetermined diffusion resistance to a measurement gas and covers the first electrode so that the first electrode is exposed to the measurement gas via the diffusion resistance means; means for introducing a reference gas having a predetermined oxygen partial pressure, for exposure of the second electrode to the reference gas; and means for applying an electric current between the first and second electrodes, to induce an electrode reaction for controlling an atmosphere adjacent to the first electrode, characterized in that: an electrochemical pumping cell is provided, which comprises: a second planar oxygen-ion conductive solid .electrolyte body (which may be the same as or different from said first electrolyte body); a third and a fourth electrode of porous structure disposed on said second planar solid electrolyte body such that the third and fourth electrodes are spaced from each other, said third electrode (which may be the same as or different from said second electrode) being exposed to an atmosphere that is substantially the same as said reference gas to which said second electrode is exposed, said fourth electrode being exposed to said measurement gas; and means for inducing a flow of electric current from said third electrode to said fourth electrode and thereby supplying an oxygen component of said measurement gas into said reference gas to which said second electrode is exposed.
Claim 2
Dependent Claim
274 words
An electrochemical device having an electrochemical sensing cell which includes: a first planar oxygen-ion conductive solid electrolyte body; a first and a second electrode of porous structure disposed on the first planar solid electrolyte body such that the first and second electrodes are spaced from each other; diffusion resistance means which has a predetermined diffusion resistance to a measurement gas and covers the first electrode so that the first electrode is exposed to the measurement gas via the diffusion resistance means; means for introducing a reference gas having a predetermined oxygen partial pressure, for exposure of the second electrode to the reference gas; and means for applying an electric current between the first and second electrodes, to induce an electrode reaction for controlling an atmosphere adjacent to the first electrode, characterized in that: an electrochemical pumping cell is provided, which comprises: a second planar oxygen-ion conductive solid .electrolyte body (which may be the same as or different from said first electrolyte body); a third and a fourth electrode of porous structure disposed on said second planar solid electrolyte body such that the third and fourth electrodes are spaced from each other, said third electrode (which may be the same as or different from said second electrode) being exposed to an atmosphere that is substantially the same as said reference gas to which said second electrode is exposed, said fourth electrode being exposed to said measurement gas; and means for inducing a flow of electric current from said third electrode to said fourth electrode and thereby supplying an oxygen component of said measurement gas into said reference gas to which said second electrode is exposed.
Claim 3
Dependent Claim
29 words
An electrochemical device according to claim 1, wherein a single planar solid electrolyte body constitutes said first and second solid electrolyte bodies of the electrochemical sensing and pumping cells.
Claim 4
Dependent Claim
37 words
An electrochemical device according to claim 1, wherein two separate planar solid electrolyte bodies constitute said first solid electrolyte body of the electrochmical sensing cell and said second solid electrolyte body of the electrochemical pumping cell, respectively.
Claim 5
Dependent Claim
44 words
An electrochemical device according to any one of claims 1-3, wherein said first and second electrodes of the electrochemical sensing cell are disposed on opposite surfaces of said first solid electrolyte body such that the first and second electrodes are aligned with each other.
Claim 6
Dependent Claim
44 words
An electrochemical device according to any one of claims 1-4, wherein said third and fourth electrodes of the electrochemical pumping cell are disposed on opposite surfaces of said second solid electrolyte body such that the third and fourth electrodes are aligned with each other.
Claim 7
Dependent Claim
39 words
An electrochemical device according to claim 3, wherein said second electrode of the electrochemical sensing cell and said third electrode of the electrochemical pumping cell are disposed on opposite sides of an electrically insulating ceramic layer of porous structure.
Claim 8
Dependent Claim
40 words
An electrochemical device according to claim 2 or 3, wherein said second electrode of the electrochemical sensing cell and said third electrode of the electrochemical pumping cell are both exposed to a reference-gas passage which communicates with the ambient air.
Claim 9
Dependent Claim
42 words
An electrochemical device according to any one of claims 1-5 and 7, wherein said second electrode of the electrochemical sensing cell and said third electrode of the electrochemical pumping cell are constituted by a single layer, or electrically connected to each other.
Claim 10
Dependent Claim
34 words
An electrochemical device according to any one of claims 1-8, wherein said diffusion resistance means comprises a porous ceramic layer disposed on said first solid electrolyte body so as to cover said first electrode.
Claim 11
Dependent Claim
63 words
An electrochemical device according to any one of claims 1-8, wherein said diffusion resistance means comprises means for defining a pin hole or thin flat space communicating with an outside space in which said measurement gas exists, said pin hole or thin flat space being open to a surface of said first electrode and dimensioned so as to provide said predetermined diffusion resistance.
Claim 12
Dependent Claim
33 words
An electrochemical device according to any one of claims 1-10, further comprising an electric heater layer disposed between said electrochemical sensing and pumping cells, or on one side of the electrochemical pumping cell.
References Cited (Backward Citations)
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