Patent US3970431A successfully refreshed from Google Patents.
US3970431A
Expired / Lapsed
US
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Carbon monoxide gas detector
Assignee: SRI International Inc
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Filing: 1975-03-31
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Granted: 1976-07-20
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Expires: 1995-03-31
Abstract
Abstract An indicator of the presence and changes in the carbon monoxide content of the air is provided by this invention. It operates by measuring the change in resistance of a silver oxide when exposed to carbon monoxide.
Inventors
- 👤 Henry Wise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:47
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/204998; Y10T436/205831
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
47 words
A method of measuring the presence and the amount of carbon monoxide present in gases comprising exposing a body consisting of silver oxide to said gases, and measuring the change of electrical conductivity of said body of silver oxide in response to carbon monoxide in said gases.
Claim 2
Independent Claim
47 words
A method of measuring the presence and the amount of carbon monoxide present in gases comprising exposing a body consisting of silver oxide to said gases, and measuring the change of electrical conductivity of said body of silver oxide in response to carbon monoxide in said gases.
Claim 3
Dependent Claim
22 words
A method as recited in claim 1 wherein said body consisting of silver oxide is a pellet of compressed silver oxide granules.
Claim 4
Dependent Claim
24 words
A method as recited in claim 1 wherein said body consisting of silver oxide is a film of silver oxide deposited on a substrate.
Claim 5
Independent Claim
81 words
A method of measuring the presence and the amount of cabon monoxide present in gases comprising immersing a body consisting of silver oxide in gases containing carbon monoxide, applying a voltage across a predetermined part of said silver oxide body, measuring the change in current flowing across said predetermined part of said silver oxide body caused by the carbon monoxide present in said gases, and displaying said change of current flowing as an indication of the amount of cabon monoxide present.
Claim 6
Independent Claim
81 words
A method of measuring the presence and the amount of cabon monoxide present in gases comprising immersing a body consisting of silver oxide in gases containing carbon monoxide, applying a voltage across a predetermined part of said silver oxide body, measuring the change in current flowing across said predetermined part of said silver oxide body caused by the carbon monoxide present in said gases, and displaying said change of current flowing as an indication of the amount of cabon monoxide present.
Claim 7
Dependent Claim
19 words
The method as recited in claim 4 wherein said body consists of a compressed pellet of silver oxide granules.
Claim 8
Dependent Claim
21 words
The method as recited in claim 4 wherein said body consists of a film of silver oxide deposited on a substrate.
Claim 9
Dependent Claim
33 words
The method as recited in claim 4 wherein said body consisting of silver oxide is doped with a high valence metal oxide selected from a group consisting of manganese oxide and cobaltic oxide.
Claim 10
Independent Claim
72 words
A method of measuring the presence and amount of carbon monoxide present in gases comprising heating a pellet consisting of of silver oxide granules for from 5 to 10 minutes in the atmosphere at a temperature on the order of 275°C, cooling said pellet to the ambient temperature, immersing said pellet in said gases, and measuring the change of electrical conductivity of said pellet caused by the carbon monoxide in said gases.
Claim 11
Independent Claim
72 words
A method of measuring the presence and amount of carbon monoxide present in gases comprising heating a pellet consisting of of silver oxide granules for from 5 to 10 minutes in the atmosphere at a temperature on the order of 275°C, cooling said pellet to the ambient temperature, immersing said pellet in said gases, and measuring the change of electrical conductivity of said pellet caused by the carbon monoxide in said gases.
Claim 12
Independent Claim
61 words
A method of measuring the presence and amount of carbon monoxide present in gases comprising exposing a pellet of compressed granules consisting of silver oxide doped with a high valence metal oxide selected from a group consisting of manganese oxide and cobaltic oxide, and measuring the change of electrical conductivity of said pellet in response to carbon monoxide in said gases.
Claim 13
Independent Claim
61 words
A method of measuring the presence and amount of carbon monoxide present in gases comprising exposing a pellet of compressed granules consisting of silver oxide doped with a high valence metal oxide selected from a group consisting of manganese oxide and cobaltic oxide, and measuring the change of electrical conductivity of said pellet in response to carbon monoxide in said gases.
References Cited (Backward Citations)
US2020305A
Cited
US3051895A
Cited
US3578409A
Cited
US3567383A
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US3547835A
Cited
US3644795A
Cited
US3699803A
Cited
US3865550A
Cited
US3821038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |