US4459577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas sensor
Assignee: Figaro Engineering Inc
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Filing: 1983-04-05
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Granted: 1984-07-10
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Expires: 2003-04-05
Abstract
Abstract A combustion gas sensor and material therefore responsive to changes in the composition of ambient atmospheres wherein the sensing element includes SnO 2 crystals having a means d of approximately 500-3200 Å and having a surface area to mass ratio S of 1-8 m 2 /g a process for making same. Preferably, the standard deviation of crystal size distribution is 0.2d.
Inventors
- 👤 Nobuaki Murakami
- 👤 Katsuyuki Tanaka
- 👤 Kousuke Ihokura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:13
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/1454; F02D41/1455
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
62 words
A combustion gas sensor element comprising: a ceramic element including SnO 2 crystals having a d, wherein d is the mean particle size, of approximately 500 to 3200 Å and having an S, wherein S is the surface area per unit mass, of approximately 1 to 8 m 2 /g; and, p1 means for connecting the ceramic element to an electric circuit.
Claim 2
Dependent Claim
62 words
A combustion gas sensor element comprising: a ceramic element including SnO 2 crystals having a d, wherein d is the mean particle size, of approximately 500 to 3200 Å and having an S, wherein S is the surface area per unit mass, of approximately 1 to 8 m 2 /g; and, p1 means for connecting the ceramic element to an electric circuit.
Claim 3
Dependent Claim
27 words
The combustion gas sensor element defined in claim 1, wherein: S is approximately 2.5 to 1.4 m 2 /g and d is approximately 1500 to 2200 Å.
Claim 4
Dependent Claim
23 words
The combustion gas sensor element defined in claim 1, further comprising: a base plate of non-conducting heat-resistant material for supporting the ceramic element.
Claim 5
Dependent Claim
31 words
The combustion gas sensor element defined in claim 3, wherein: the means for connecting the ceramic element to an electric circuit comprises a pair of electrodes embedded in the ceramic element.
Claim 6
Dependent Claim
16 words
The combustion gas sensor element defined in claim 4, wherein: the electrodes are a platinum/rhodium alloy.
Claim 7
Dependent Claim
20 words
The combustion gas sensor element defined in claim 5, wherein: the electrodes attach the ceramic element to the base plate.
Claim 8
Dependent Claim
25 words
The combustion gas sensor element as in any one of claims 1-6, wherein: the standard deviation in crystal size distribution is at least 0.2 d.
Claim 9
Dependent Claim
33 words
A combustion gas sensor element as recited in claim 7, further comprising: at least one component admixed with the ceramic element selected from the group consisting of alumina, amorphous silica, platinum and rhoduim.
Claim 10
Dependent Claim
34 words
A material for combustion gas sensor elements, which comprises: SnO 2 crystals having a d of approximately 500 to 3200 A and the standard deviation of crystal size distribution is at least 0.2 d.
Claim 11
Dependent Claim
34 words
A material for combustion gas sensor elements, which comprises: SnO 2 crystals having a d of approximately 500 to 3200 A and the standard deviation of crystal size distribution is at least 0.2 d.
Claim 12
Dependent Claim
30 words
The material for combustion gas sensor element as defined in claim 9, further comprising: at least one component selected from the group consisting of alumina, amorphous silica platinum and rhodium.
References Cited (Backward Citations)
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US4260978A
Cited
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Cited
US4228128A
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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) | 1987-07-10 | 1988-01-09 | 1988-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-10 | 1992-01-09 | 1992-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-10 | 1996-01-09 | 1996-07-10 | $7700.00 | Window Closed / Lapsed |