Patent US4731226A successfully refreshed from Google Patents.
US4731226A
Expired / Lapsed
US
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Gas sensor
Assignee: Figaro Engineering Inc
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Filing: 1986-06-18
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Granted: 1988-03-15
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Expires: 2006-06-18
Abstract
Abstract A gas sensor in which a compound of rhenium is added to tin oxide (SnO2). Rhenium inhibits the sensor from lowering its resistance over time and in particular increases its durability against overheating. Rhenium is preferably used together with vanadium. Rhenium is preferably added by impregnation in order to maintain temperature characteristic of the sensor.
Inventors
- 👤 Kei Takahata
- 👤 Yoshinobu Matsuura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:55
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/62; G01N27/02; G01N27/04; G01N27/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
45 words
A gas sensor which comprises: an electrode; and a gas sensitive element which is connected to said electrode, said gas sensitive element comprising: SnO 2 ; and at least one rhenium containing material selected from the group consisting of elemental rhenium and oxides of rhenium.
Claim 2
Dependent Claim
45 words
A gas sensor which comprises: an electrode; and a gas sensitive element which is connected to said electrode, said gas sensitive element comprising: SnO 2 ; and at least one rhenium containing material selected from the group consisting of elemental rhenium and oxides of rhenium.
Claim 3
Dependent Claim
49 words
A gas sensor of claim 1 wherein said rhenium containing material is substantially uniformly dispersed throughout said gas sensitive element and said rhenium containing material is present in a weight ratio of about 1 to about 150 mg of said rhenium containing material per gram of SnO 2 .
Claim 4
Dependent Claim
23 words
A gas sensor of claim 1 wherein said rhenium containing material is substantially uniformly dispersed on the surface of said gas sensitive element.
Claim 5
Dependent Claim
17 words
A gas sensor of claims 1 or 3 wherein said gas sensitive element further comprises: vanadium oxide.
Claim 6
Dependent Claim
29 words
A gas sensor of claim 1 wherein said rhenium containing material is substantially uniformly dispersed within a thermal resistant insulating material which is incorrporated into the gas sensitive element.
Claim 7
Dependent Claim
14 words
A gas sensor of claim 5 wherein said gas sensitive element further comprises silica.
References Cited (Backward Citations)
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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) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |