Patent US5234567A successfully refreshed from Google Patents.
US5234567A
Expired / Lapsed
US
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Gas sensor
Assignee: City Technology Ltd
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Filing: 1992-01-23
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Granted: 1993-08-10
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Expires: 2012-01-23
Abstract
Abstract An electrochemical gas sensor for sensing an alkaline gas such as ammonia. The sensor comprises at least sensing and counter electrodes provided in a cell containing an aqueous electrolyte, the cell further including a diffusion barrier to restrict the access of gas to the cell, and a chemical species with which the gas reacts in use to form a product which is more electrochemically active than the gas. The chemical species is one of iodine, Nesslers reagent and a solution of manganous and silver nitrates.
Inventors
- 👤 Bryan S. Hobbs
- 👤 Yat S. Chan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:46
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N33/0054; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
85 words
An electrochemical gas sensor for sensing an alkaline gas, the sensor comprising at least sensing and counter electrodes provided in a cell containing an aqueous electrolyte, the cell further including a diffusion barrier to restrict the access of gas to the cell, and a chemical species with which the gas reacts ensue to form a product which is more electrochemically active than the gas, wherein said chemical species is one of: a) iodine; b) Nesslers reagent; and c) a solution of manganous and silver nitrates.
Claim 2
Dependent Claim
85 words
An electrochemical gas sensor for sensing an alkaline gas, the sensor comprising at least sensing and counter electrodes provided in a cell containing an aqueous electrolyte, the cell further including a diffusion barrier to restrict the access of gas to the cell, and a chemical species with which the gas reacts ensue to form a product which is more electrochemically active than the gas, wherein said chemical species is one of: a) iodine; b) Nesslers reagent; and c) a solution of manganous and silver nitrates.
Claim 3
Dependent Claim
15 words
A sensor according to claim 1 for detecting ammonia, wherein said chemical species is iodine.
Claim 4
Dependent Claim
18 words
A sensor according to claim 2, wherein said iodine is bound to another compound to reduce its volatility.
Claim 5
Dependent Claim
14 words
A sensor according to claim 3, wherein said iodine is bound chemically to starch.
Claim 6
Dependent Claim
30 words
A sensor according to claim 1, wherein said sensor further comprises a permeation device containing an iodine source so as to provide a controlled release of iodine into the electrolyte.
Claim 7
Dependent Claim
13 words
A sensor according to claim 5, wherein said iodine source comprises solid iodine.
Claim 8
Dependent Claim
24 words
A sensor according to claim 1, wherein said diffusion barrier is at least one of a gas phase diffusion barrier and a Knudsen barrier.
Claim 9
Dependent Claim
11 words
A sensor according to claim 1, further comprising a reference electrode.
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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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |