EP0361692A2
Expired / Lapsed
EP
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Sensor for determining relative amount of oxygen containing gas in a gas mixture
Assignee: Ford-Werke GmbH
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Filing: 1989-08-31
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Granted: —
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Expires: 2009-08-31
Abstract
Abstract The electrochemical device and method measures the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture containing at least a second oxygen containing gas which is capable of being pumped out or disassociated at a voltage less than that which is capable of disassociating the measurement gas. The mixture may comprise, e.g., O₂, CO₂, and H₂O. Two electrochemical pump cells and a support structure form a restricted volume (40) in communication through an aperture to the gas mixture. The device comprises a first external electrical circuit means across a first pump cell (21) for applying a voltage to cause molecules of substantially all second oxygen containing gas molecules inside the restricted volume to be pumped out from the restricted volume (40) or disassociated. The device also comprises a second external electrical circuit means across a second pump cell (31) causes for applying a voltage to disassociate only of substantially all measurement gas molecules inside the volume. The device further comprises a third external electrical circuit means to measure the current flowing in the second pump cell (31), this current being proportional to the relative amount of measurement gas in the gas mixture. The invention also is directed to a planar electrochemical device and method for measuring the relative percentage of a measure gas in a gas mixture like that described above.
Inventors
- 👤 Eleftherios M. Logothetis
- 👤 Richard E. Soltis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 05:54
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/417
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
324 words
An electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said device comprising, a first solid electrochemical oxygen pump cell (21) having a first pair of opposed electrodes (23,24), a second solid electrochemical oxygen pump cell (31) having a second pair of opposed electrodes (33,34), a supporting structure coupled to said first and second pump cells to form with them a restricted volume (40), at least one aperture (41) for providing communication between said restricted volume (40) and said gas mixture, a first external electrical circuit means coupled to said first pump cell (21) for applying a first voltage across said first pump cell to negatively bias a first pump cell electrode of said first pair of opposed electrodes inside said restricted volume (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said restricted volume to be pumped out from said restricted volume (40) or disassociated by a current flowing through said first pump cell and (ii) insufficiently disassociate said measurement gas, a second external electrical circuit means coupled to said second pump cell (31) for applying a second voltage across said second pump cell to negatively bias a second pump cell electrode of said second pair of opposed electrodes inside said volume sufficiently to disassociate only substantially all said measurement gas inside said restricted volume by a current flowing through said second pump cell, and a third external electrical circuit means coupled to said second pump cell to measure said current flowing through said second pump cell, said second pump cell current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 2
Dependent Claim
324 words
An electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said device comprising, a first solid electrochemical oxygen pump cell (21) having a first pair of opposed electrodes (23,24), a second solid electrochemical oxygen pump cell (31) having a second pair of opposed electrodes (33,34), a supporting structure coupled to said first and second pump cells to form with them a restricted volume (40), at least one aperture (41) for providing communication between said restricted volume (40) and said gas mixture, a first external electrical circuit means coupled to said first pump cell (21) for applying a first voltage across said first pump cell to negatively bias a first pump cell electrode of said first pair of opposed electrodes inside said restricted volume (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said restricted volume to be pumped out from said restricted volume (40) or disassociated by a current flowing through said first pump cell and (ii) insufficiently disassociate said measurement gas, a second external electrical circuit means coupled to said second pump cell (31) for applying a second voltage across said second pump cell to negatively bias a second pump cell electrode of said second pair of opposed electrodes inside said volume sufficiently to disassociate only substantially all said measurement gas inside said restricted volume by a current flowing through said second pump cell, and a third external electrical circuit means coupled to said second pump cell to measure said current flowing through said second pump cell, said second pump cell current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 3
Dependent Claim
296 words
An electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said electrochemical device including, a generally planar first electrochemical oxygen pump cell including a relatively dense platelet with one of a pair of porous electrodes on each of two spaced sides of said platelet, a first porous layer deposited on one electrode of said first pump cell, a generally planar second electrochemical oxygen pump cell including a first porous electrode, a second porous layer and a second porous electrode deposited successively on said first porous layer, a second cell external electrical circuit means coupled to said second pump cell for applying a first voltage across said second pump cell to positively bias said second electrode (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said first porous layer to be pumped out or disassociated by a current flowing through said second pump cell and (ii) insufficiently disassociate said measurement gas, a first cell external electrical circuit means coupled to said first pump cell for applying a second voltage across said first pump cell to positively bias the exposed electrode of said first pump cell sufficiently to disassociate only substantially all of said measurement gas molecules inside said first porous layer; and a third external electrical circuit means coupled to said first pump cell to measure said current flowing through said first pump cell, said current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 4
Dependent Claim
296 words
An electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said electrochemical device including, a generally planar first electrochemical oxygen pump cell including a relatively dense platelet with one of a pair of porous electrodes on each of two spaced sides of said platelet, a first porous layer deposited on one electrode of said first pump cell, a generally planar second electrochemical oxygen pump cell including a first porous electrode, a second porous layer and a second porous electrode deposited successively on said first porous layer, a second cell external electrical circuit means coupled to said second pump cell for applying a first voltage across said second pump cell to positively bias said second electrode (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said first porous layer to be pumped out or disassociated by a current flowing through said second pump cell and (ii) insufficiently disassociate said measurement gas, a first cell external electrical circuit means coupled to said first pump cell for applying a second voltage across said first pump cell to positively bias the exposed electrode of said first pump cell sufficiently to disassociate only substantially all of said measurement gas molecules inside said first porous layer; and a third external electrical circuit means coupled to said first pump cell to measure said current flowing through said first pump cell, said current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 5
Dependent Claim
38 words
An electrochemical device as claimed in claim 1 or 2, wherein said first and second external circuit means are adapted to apply said first and second voltages, respectively, in modes independently selected from (i) continuous and (ii) intermittent.
Claim 6
Dependent Claim
31 words
An electrochemical device as claimed in claim 3, wherein said third external electrical circuit means is adapted to measure said current in modes independently selected from (i) continuous and (ii) intermittent.
Claim 7
Dependent Claim
26 words
An electrochemical device as claimed in claim 1 or 2, further including a heater to maintain the temperature of the device above at least about 500/C.
Claim 8
Dependent Claim
48 words
An electrochemical device as claimed in claim 1 or 2, wherein said gas mixture is air, said measurement gas is H₂O and said first external circuit means is adapted to apply a first voltage across said first pump cell in the range of about 0.2 to 1.0 volts.
Claim 9
Dependent Claim
35 words
An electrochemical device as claimed in claim 6, wherein said second external circuit means is adapted to apply a second voltage across said second pump cell in the range of about 1.3 to 2.0 volts.
Claim 10
Dependent Claim
26 words
An electrochemical device as claimed in claim 1, further comprising a porous layer deposited on top of said second pump cell electrode located inside said volume.
Claim 11
Dependent Claim
34 words
An electrochemical device as claimed in claim 1, further comprising a wall inside said volume, said wall dividing said volume into two compartments which communicate with each other through an aperture in said wall.
Claim 12
Independent Claim
298 words
A method employing an electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said method comprising the steps of, providing communication between said gas mixture and a restricted volume of an electrochemical device, which device comprises, a first solid electrochemical oxygen pump cell having a first pair of opposed electrodes, a second solid electrochemical oxygen pump cell having a second pair of opposed electrodes, a supporting structure coupled to said first and second pump cells to form with them said restricted volume, at least one aperture for providing communication between said restricted volume and said gas mixture, applying a first voltage across said first pump cell to negatively bias a first pump cell electrode of said first pair of opposed electrodes inside said restricted volume (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said restricted volume to be pumped out from said restricted volume or disassociated by a current flowing through said first pump cell and (ii) insufficiently disassociate the measurement gas, applying a second voltage across said second pump cell to negatively bias a second pump cell electrode of said second pair of opposed electrodes inside said restricted volume sufficiently to disassociate only substantially all said measurement gas inside said restricted volume by a current flowing through said second pump cell, measuring said current flowing through said second pump cell, said second pump cell current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 13
Independent Claim
298 words
A method employing an electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said method comprising the steps of, providing communication between said gas mixture and a restricted volume of an electrochemical device, which device comprises, a first solid electrochemical oxygen pump cell having a first pair of opposed electrodes, a second solid electrochemical oxygen pump cell having a second pair of opposed electrodes, a supporting structure coupled to said first and second pump cells to form with them said restricted volume, at least one aperture for providing communication between said restricted volume and said gas mixture, applying a first voltage across said first pump cell to negatively bias a first pump cell electrode of said first pair of opposed electrodes inside said restricted volume (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said restricted volume to be pumped out from said restricted volume or disassociated by a current flowing through said first pump cell and (ii) insufficiently disassociate the measurement gas, applying a second voltage across said second pump cell to negatively bias a second pump cell electrode of said second pair of opposed electrodes inside said restricted volume sufficiently to disassociate only substantially all said measurement gas inside said restricted volume by a current flowing through said second pump cell, measuring said current flowing through said second pump cell, said second pump cell current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 14
Independent Claim
277 words
A method employing an electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said method comprising the steps of, providing communication between said gas mixture and a first porous layer of an electrochemical device, which device comprises, a generally planar first electrochemical oxygen pump cell including a relatively dense platelet with one of a pair of porous electrodes on each of two spaced sides of said platelet, a first porous layer deposited on one electrode of said first pump cell, a generally planar second electrochemical oxygen pump cell including a first porous electrode, a second porous layer and a second porous electrode deposited successively on said first porous layer, applying a first voltage across said second pump cell to positively bias said second electrode (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said first porous to be pumped out or disassociated by a current flowing through said second pump cell and (ii) insufficiently disassociate said measurement gas, applying a second voltage across said first pump cell to positively bias the exposed electrode of said first pump cell sufficiently to disassociate only substantially all of said measurement gas molecules inside said first porous layer, and measuring said current flowing through said first pump cell, said current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 15
Independent Claim
277 words
A method employing an electrochemical oxygen pumping device for measuring the relative amount of a measurement gas consisting essentially of at least one oxygen containing gas in a gas mixture comprising in addition at least a second oxygen containing gas which is capable of being pumped out of said device or disassociated at a voltage less than that which is capable of disassociating said measurement gas, said method comprising the steps of, providing communication between said gas mixture and a first porous layer of an electrochemical device, which device comprises, a generally planar first electrochemical oxygen pump cell including a relatively dense platelet with one of a pair of porous electrodes on each of two spaced sides of said platelet, a first porous layer deposited on one electrode of said first pump cell, a generally planar second electrochemical oxygen pump cell including a first porous electrode, a second porous layer and a second porous electrode deposited successively on said first porous layer, applying a first voltage across said second pump cell to positively bias said second electrode (i) sufficiently to cause substantially all said second oxygen containing gas molecules inside said first porous to be pumped out or disassociated by a current flowing through said second pump cell and (ii) insufficiently disassociate said measurement gas, applying a second voltage across said first pump cell to positively bias the exposed electrode of said first pump cell sufficiently to disassociate only substantially all of said measurement gas molecules inside said first porous layer, and measuring said current flowing through said first pump cell, said current being proportional to the relative amount of said measurement gas in said gas mixture.
Claim 16
Dependent Claim
28 words
A method as claimed in claim 10 or 11, wherein said first and second external voltages are applied in modes independently selected from (i) continuous and (ii) intermittent.
Claim 17
Dependent Claim
22 words
A method as claimed in claim 12, wherein said current is measured in modes independently selected from (i) continuous and (ii) intermittent.
Claim 18
Dependent Claim
46 words
The method as claimed in claim 10, wherein said electrode of said second pump cell inside said restricted volume is separated from the restricted volume by a porous layer so that communication to said restricted volume from said second pump cell is through said porous layer.
Claim 19
Dependent Claim
48 words
A method as claimed in claim 10, wherein said restricted volume is divided into two compartments which communicate with each other through an aperture in a wall inside said restricted volume so that communication between said two electrochemical pump cells on opposing sides of the wall is controlled.
References Cited (Backward Citations)
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