US3607084A
Expired / Lapsed
US
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Combustible gas measurement
Assignee: Sun Electric Corp
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Filing: 1968-12-02
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Granted: 1971-09-21
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Expires: 1988-12-02
Abstract
Abstract The measurement of combustible gases comprises passing a stream of gas containing the combustible gases over a conductive metal wire coated with a thin catalytic coating of a mixture of thorium oxide and black palladium powder and/or black platinum powder. Electrical current is passed through the conductor wire to raise the temperature of the wire to a first temperature at which the oxidation of the combustible gases is initiated in the presence of the catalytic effect produced by the coating. The oxidation of the combustible gases substantially elevates the temperature of the conductor wire, changing its electrical resistance, the amount of heat generated during oxidation being directly proportional to the quantity of combustible gases in the gas stream. The metal conductor wire is preferably formed of a base metal in which the change in resistivity between the first and elevated temperatures is substantially equal to or greater than the change in resistivity of platinum between those temperatures.
Inventors
- 👤 Robert J Mackey
- 👤 Ihor B Karpowycz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:40
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16; B; B01; B01J; B01J35/00; B01J35/30; B01J35/33; F; F01; F01N; F01N3/00; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/204998; Y10T436/21; Y10T436/218; Y10T436/22; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
27 words
The method of claim 1 where said powdered platinum group metal is a metal selected from the group consisting of black platinum, black palladium and mixtures thereof.
Claim 2
Dependent Claim
44 words
The method of claim 1 wherein the temperature change is sensed by heating a base metal conduct or from said first temperature to substantially said second temperature and measuring the change in electrical resistivity of said metallic conductor between said first and second temperatures.
Claim 3
Dependent Claim
26 words
The method of claim 3 wherein said metallic conductor is a base metal selected from the groUp consisting of titanium, stainless steel, and a nickel alloy.
Claim 4
Dependent Claim
22 words
The method of claim 4 wherein said stainless steel is T 434 and said nickel alloy is 70% nickel and 30% iron.
Claim 5
Dependent Claim
42 words
The method of claim 3 wherein said base metal conductor is a metal in which the change in electrical resistivity between said first and second temperatures is substantially equal to or greater than the change in resistivity of platinum between said temperatures.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein said metal oxide is thorium oxide.
Claim 7
Dependent Claim
30 words
The method of claim 1 wherein said volume of gases are exhaust gases from a combustion engine and said combustible gases generally comprise at least one of CO, H2and CxHn.
Claim 8
Dependent Claim
41 words
An element for measuring the quantity of combustible gases in a volume of gas comprising, a metallic conductor, and a rigid coating on said conductor comprising a catalytic mixture of a metal oxide and a powdered metal of the platinum group.
Claim 9
Dependent Claim
52 words
The measuring element of claim 9 wherein said metallic conductor is a metal in which the change in electrical resistivity when the metal is heated over a given temperature range is substantially equal to or greater than the change in resistivity of platinum when platinum is heated over said given temperature range.
Claim 10
Dependent Claim
27 words
The measuring element of claim 9 wherein said metallic conductor is a base metal selected from the group consisting of titanium, stainless steel, and a nickel alloy.
Claim 11
Dependent Claim
24 words
The measuring element of claim 11 wherein said stainless steel is T 434 and wherein said nickel alloy is 70% nickel and 30% iron.
Claim 12
Dependent Claim
28 words
The measuring element of claim 9 wherein said powdered platinum group metal is a metal selected from the group consisting of black palladium, black platinum and mixtures thereof.
Claim 13
Dependent Claim
13 words
The measuring element of claim 9 wherein said metal oxide is thorium oxide.
Claim 14
Independent Claim
176 words
A system for measuring the quantity of combustible gases in a volume of gas comprising: a chamber for containing the volume of gas, a pair of electrically conductive metallic wires located in said chamber in the volume of gas, electric power supply means for supplying an electric current flow through said wires, a coating on one of said wires substantially entirely covering the surface of said wire exposed to said volume of gas, said coating comprising a catalytic mixture of a metal oxide and a powdered metal of the platinum group, heating means for elevating the temperature of said volume of gas to a first temperature at which the combustible gases in the volume of gas are oxidized in the presence of said catalytic mixture of metal oxide and platinum group metal, and measuring means for measuring the electrical resistance change in said one wire caused by the elevation in temperature of said wire from said first temperature to a higher temperature due to the heat of combustion produced by the oxidation of the combustible gases.
Claim 15
Dependent Claim
24 words
The system of claim 15 wherein said measuring means comprises a Wheatstone bridge, said pair of metallic wires comprising one of the resistances therein.
Claim 16
Dependent Claim
41 words
The system of claim 15 wherein said metallic wire is a metal in which the change in electrical resistivity between said first and higher temperatures is substantially equal to or greater then the change in resistivity of platinum between said temperatures.
Claim 17
Dependent Claim
25 words
The system of claim 15 wherein said wire is a base metal selected from the group consisting of titanium, stainless steel and a nickel alloy.
Claim 18
Dependent Claim
25 words
The system of claim 15 wherein said powdered platinum group metal is selected from the group consisting of black palladium, black platinum and mixtures thereof.
Claim 19
Dependent Claim
12 words
The system of claim 19 wherein said metal oxide is thorium oxide.
Claim 20
Dependent Claim
35 words
The system of claim 15 wherein said heating means comprises said conductive metallic wire, said power supply means heating said metallic wire to substantially said first temperature to initiate the Oxidation of the combustible gases.
References Cited (Backward Citations)
US2030283A
Cited
US2273981A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |