US4233142A
Expired / Lapsed
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Electrochemical measuring cell
Assignee: BBC Brown Boveri AG Germany
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Filing: 1978-08-22
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Granted: 1980-11-11
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Expires: 1998-08-22
Abstract
Abstract An electrochemical measuring cell for determining the oxygen content in exhaust gases from internal-combustion engines and combustions having an ion-conducting solid electrolyte with a measuring electrode as a first layer on the solid electrolyte and a reference electrode as a second layer on the solid electrolyte. A third layer coats the first layer measuring electrode and contains a material with a high partial oxygen pressure to obtain a characteristic U=f(λ) which has a small slope in the range of the air number of about 1; a material with a medium partial oxygen pressure to obtain a characteristic with a medium slope; and a material with low partial oxygen pressure to obtain a characteristic with a steep slope.
Inventors
- 👤 Franz-Josef Rohr
- 👤 Hubert Holick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:08
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/407; G01N27/4075; G01N27/4076
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
256 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ions through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a medium partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a medium slope in the range of the air number of about 1 wherein a medium slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of between 0.1 and 0.5 and wherein the third layer contains a mixture of an inert ceramic material with a material of the formula Me.sub.x.sup.I Me.sub.y.sup.II Me.sup.III O.sub.3 where Me I is a member selected from the group consisting of lanthanum, gadolinium and praseodymium; Me II is a member selected from the group consisting of strontium, calcium and barium; and Me III is a member selected from the group consisting of manganese, nickel, cobalt and chromium, and x has a value of 0.74 to 0.92, and y has a value of 0.08 to 0.26.
Claim 2
Dependent Claim
256 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ions through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a medium partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a medium slope in the range of the air number of about 1 wherein a medium slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of between 0.1 and 0.5 and wherein the third layer contains a mixture of an inert ceramic material with a material of the formula Me.sub.x.sup.I Me.sub.y.sup.II Me.sup.III O.sub.3 where Me I is a member selected from the group consisting of lanthanum, gadolinium and praseodymium; Me II is a member selected from the group consisting of strontium, calcium and barium; and Me III is a member selected from the group consisting of manganese, nickel, cobalt and chromium, and x has a value of 0.74 to 0.92, and y has a value of 0.08 to 0.26.
Claim 3
Dependent Claim
28 words
Electrochemical measuring cell according to claim 1, characterized by the feature that the mixture has a content of the inert material of about 10% to 99% by weight.
Claim 4
Dependent Claim
21 words
Electrochemical measuring cell according to claim 2, wherein the content of the inert material is about 85% to 97% by weight.
Claim 5
Dependent Claim
22 words
Electrochemical measuring cell according to claim 1, wherein a third layer is arranged on the first layer and on the second layer.
Claim 6
Dependent Claim
18 words
Electrochemical measuring cell according to claim 4, wherein the first and the third layers contain the same material.
Claim 7
Dependent Claim
14 words
Electrochemical measuring cell according to claim 5, wherein all layers contain the same material.
Claim 8
Dependent Claim
192 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ions through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a low partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a steep slope in the range of the air number of about 1 wherein a steep slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of about 0.05 to 0.1 and wherein the third layer contains a material of the formula La.sub.x Sr.sub.(1-x) Cr.sub.x Ni.sub.(1-x) O.sub.3 where x has a value of 0.7 to 0.95.
Claim 9
Dependent Claim
192 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ions through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a low partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a steep slope in the range of the air number of about 1 wherein a steep slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of about 0.05 to 0.1 and wherein the third layer contains a material of the formula La.sub.x Sr.sub.(1-x) Cr.sub.x Ni.sub.(1-x) O.sub.3 where x has a value of 0.7 to 0.95.
Claim 10
Dependent Claim
16 words
Electrochemical measuring cell according to claim 7, wherein x has a value of 0.8 to 0.85.
Claim 11
Dependent Claim
22 words
Electrochemical measuring cell according to claim 7, wherein a third layer is arranged on the first layer and on the second layer.
Claim 12
Dependent Claim
18 words
Electrochemical measuring cell according to claim 9, wherein the first and the third layers contain the same material.
Claim 13
Dependent Claim
14 words
Electrochemical measuring cell according to claim 10, wherein all layers contain the same material.
Claim 14
Dependent Claim
184 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ion through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a low partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a steep slope in the range of the air number of about 1 wherein a steep slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of about 0.05 to 0.1 and wherein the third layer contains a material of the formula Co Cr 2 O 4 .
Claim 15
Dependent Claim
184 words
In an electrochemical measuring cell for determining the oxygen content in gases, particularly in exhaust gases from internal-combustion engines or combustion chambers, having an ion-conducting solid electrolyte for passage of oxygen ion through the solid electrolyte with a measuring electrode disposed as a first layer on a surface of the ion-conducting solid electrolyte and a reference electrode disposed as a second layer on a surface of the ion-conducting solid electrolyte opposite the first layer, the combination therewith of a catalytically active porous third layer coating the first layer measuring electrode, said third layer containing a material with a low partial oxygen pressure to obtain a change in voltage from the electrochemical measuring cell with change in air number with a characteristic which has a steep slope in the range of the air number of about 1 wherein a steep slope means an approximately linear voltage change of the measuring cell of about 500 mV corresponds to a change of the air number of about 0.05 to 0.1 and wherein the third layer contains a material of the formula Co Cr 2 O 4 .
Claim 16
Dependent Claim
22 words
Electrochemical measuring cell according to claim 12, wherein a third layer is arranged on the first layer and on the second layer.
Claim 17
Dependent Claim
18 words
Electrochemical measuring cell according to claim 13, wherein the first and the third layers contain the same material.
Claim 18
Dependent Claim
14 words
Electrochemical measuring cell according to claim 14, wherein all layers contain the same material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |