US3852169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of carbon monoxide in gas mixtures
Assignee: EIDP Inc
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Filing: 1972-11-01
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Granted: 1974-12-03
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Expires: 1992-11-01
Abstract
Abstract A selective electrochemical method for measuring carbon monoxide in admixture with other electrochemically oxidizable gases, for example, hydrogen, hydrocarbons and oxides of nitrogen, and especially exhaust gases from internal combustion engines, which method comprises supplying the gas mixture to an anodic electrode to oxidize the CO to CO2 while simultaneously supplying an O2containing gas to a cathodic electrode to reduce the O2 to O , said electrodes being separated by an electrolyte, and determining the CO content by directly correlating the current which is produced and measured in an external circuit with a known CO standard.
Inventors
- 👤 W Wolfe
- 👤 E Kring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:17
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
209 words
METHOD OF MEASURING THE CONCENTRATION OF CARBON MONOXIDE IN INTERNAL COMBUSTION ENGINE EXHAUST GAS, SAID EXHAUST GAS COMPRISES CARBON MONOXIDE AND OTHER REDUCTANT GASES, THE VOLUME RATIO OF THE OTHER REDUCTANT GASES TO CO BEING IN THE RANGE 0.1:1 TO 3.0:1, THE METHOD COMPRISING THE STEPS: A. SUPPLYING SIMULATED OR ACTUAL INTERNAL COMBUSTION EXHAUST GAS CONTAIN9NG A KNOWN CONCENTRATION OF CARBON MONOXIDE SAID SIMULATED GAS CONTAINING A CONCENTRATION OF CABON MONOXIDE EQUIVALENT TO THAT IN THE ACTUAL GAS, AT A CONSTANT FLOW RATE AND TEMPERATURE, TO A GAS PERMEABLE, HYDROPHOBIC, ELECTRONICALLY CONDUCTIVE ANODIC ELECTRODE OF AN ELECTROCHEMICAL CELL WHICH IS OPERATED AT A TEMPERATURE WITHIN THE RANGE 80-320*F., WHICH ELECTRODE IS CAPABLE OF EFFECTING ELECTROCHEMICAL OXIDATION OF CARBON MONOXIDE TO CARBON DIOXIDE AND IS SEPARATED FROM A CATHODIC ELECTRODE IN THE CELL BY AN IONICALLY CONDUCTIVE ELECTROLYTE WHICH IS STABLE AT THE CELL OPERATING TEMPERATURE, B. AT THE SAME TIME SUPPLYING AN OXYGEN-CONTAINING GAS AT A CONSTANT FLOW RATE AND TEMPERAURE TO THE CATHODIC ELECTRODE WHICH IS A GAS PERMEABLE, HYDROPHOBIC, ELECTRONICALLY CONDUCTIVE ELECTRODE WHICH IS CAPABLE OF EFFECTING ELECTROCHEMICAL REDUCTION OF OXYGEN TO O=, C. MEASURING THE RESULTANT CURRENT OR VOLTAGE GENERATED IN THE ELECTROCHEMICALLY STOICHIOMETRIC ANODIC AND CATHODIC REATIONS IN AN EXTERNAL CIRCUIT BETWEEN THE TWO ELECTRODES,
Claim 2
Dependent Claim
209 words
METHOD OF MEASURING THE CONCENTRATION OF CARBON MONOXIDE IN INTERNAL COMBUSTION ENGINE EXHAUST GAS, SAID EXHAUST GAS COMPRISES CARBON MONOXIDE AND OTHER REDUCTANT GASES, THE VOLUME RATIO OF THE OTHER REDUCTANT GASES TO CO BEING IN THE RANGE 0.1:1 TO 3.0:1, THE METHOD COMPRISING THE STEPS: A. SUPPLYING SIMULATED OR ACTUAL INTERNAL COMBUSTION EXHAUST GAS CONTAIN9NG A KNOWN CONCENTRATION OF CARBON MONOXIDE SAID SIMULATED GAS CONTAINING A CONCENTRATION OF CABON MONOXIDE EQUIVALENT TO THAT IN THE ACTUAL GAS, AT A CONSTANT FLOW RATE AND TEMPERATURE, TO A GAS PERMEABLE, HYDROPHOBIC, ELECTRONICALLY CONDUCTIVE ANODIC ELECTRODE OF AN ELECTROCHEMICAL CELL WHICH IS OPERATED AT A TEMPERATURE WITHIN THE RANGE 80-320*F., WHICH ELECTRODE IS CAPABLE OF EFFECTING ELECTROCHEMICAL OXIDATION OF CARBON MONOXIDE TO CARBON DIOXIDE AND IS SEPARATED FROM A CATHODIC ELECTRODE IN THE CELL BY AN IONICALLY CONDUCTIVE ELECTROLYTE WHICH IS STABLE AT THE CELL OPERATING TEMPERATURE, B. AT THE SAME TIME SUPPLYING AN OXYGEN-CONTAINING GAS AT A CONSTANT FLOW RATE AND TEMPERAURE TO THE CATHODIC ELECTRODE WHICH IS A GAS PERMEABLE, HYDROPHOBIC, ELECTRONICALLY CONDUCTIVE ELECTRODE WHICH IS CAPABLE OF EFFECTING ELECTROCHEMICAL REDUCTION OF OXYGEN TO O=, C. MEASURING THE RESULTANT CURRENT OR VOLTAGE GENERATED IN THE ELECTROCHEMICALLY STOICHIOMETRIC ANODIC AND CATHODIC REATIONS IN AN EXTERNAL CIRCUIT BETWEEN THE TWO ELECTRODES,
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the exhaust gas is swept into the anodic electrode with an inert gas.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein a sample of the exhaust gas is isolated and then swept into the anodic electrode with air.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the electrolyte is an aqueous acid electrolyte sorbed onto a gas impermeable film consisting of a fibrous inorganic core having interconnecting pores.
Claim 6
Dependent Claim
14 words
The method of claim 4 wherein the aqueous acid electrolyte is aqueous phosphoric acid.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein the electrolyte is contained in a matrix.
Claim 8
Dependent Claim
18 words
The method of claim 6 wherein the matrix is a film of zirconium pyrophosphate and a polytetrafluoroethylene binder.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein the cell is operated at a temperature within the range 160*-210*F.
Claim 10
Dependent Claim
11 words
The method of claim 1 wherein the oxygen-containing gas is air.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein the cathodic electrode contains 5-10 milligrams/cm.2 of platinum black.
Claim 12
Dependent Claim
43 words
The method of claim 1 wherein the external circuit between the two electrodes comprises in series a current measuring means and a variable resistor having a combined resistance which is less than that required to substantially impede the flow of the resultant current.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |