US4407778A
Expired / Lapsed
US
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Freon gas detecting element
Assignee: Toshiba Corp
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Filing: 1981-08-18
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Granted: 1983-10-04
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Expires: 2001-08-18
Abstract
Abstract Freon gas detecting element for detecting the presence of freon gas with of a pair of electrodes, a gas detecting body made of a metal oxide semiconductor and covering the pair of electrodes, and a catalytic layer coated on the gas detecting body. The catalyst layer is made of at least one element selected from the group consisting of V, Mo and W supported by one catalyst carrier selected from the group consisting of Al 2 O 3 , SiO 2 , and SiO.sub. 2 - Al 2 O 3 .
Inventors
- 👤 Masayuki Shiratori
- 👤 Masaki Katsura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:18
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; Y; Y10; Y10T; Y10T436/00; Y10T436/19; Y10T436/196666
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
109 words
A freon gas detecting element comprising: a pair of electrodes; a gas detecting body made of metal oxide semiconductor and covering said pair of electrodes; and a catalyst layer coated on said gas detecting body, said catalyst layer being made of V and W supported by one catalyst carrier selected from the group consisting of Al 2 O 3 , SiO 2 , and SiO 2 -Al 2 O 3 , the amount of V in said catalyst layer being limited from about 0.1 wt % to about 50 wt %, and the atomic ratio (W/V) between said V and W being limited from about 0.05 to about 0.5.
Claim 2
Dependent Claim
109 words
A freon gas detecting element comprising: a pair of electrodes; a gas detecting body made of metal oxide semiconductor and covering said pair of electrodes; and a catalyst layer coated on said gas detecting body, said catalyst layer being made of V and W supported by one catalyst carrier selected from the group consisting of Al 2 O 3 , SiO 2 , and SiO 2 -Al 2 O 3 , the amount of V in said catalyst layer being limited from about 0.1 wt % to about 50 wt %, and the atomic ratio (W/V) between said V and W being limited from about 0.05 to about 0.5.
Claim 3
Dependent Claim
109 words
A freon gas detecting element comprising: a pair of electrodes; a gas detecting body made of metal oxide semiconductor spread on said pair of electrodes; and a catalyst layer coated on said gas detecting body, said layer being made of V and Mo supported by one catalyst carrier selected from the group consisting of Al 2 O 3 , SiO 2 , and SiO 2 -Al 2 O 3 , the amount of said V in said catalyst layer being limited from about 0.1 wt % to about 50 wt % and the atomic ratio (Mo/V) between said V and Mo being limited from about 0.05 to about 0.5.
Claim 4
Dependent Claim
109 words
A freon gas detecting element comprising: a pair of electrodes; a gas detecting body made of metal oxide semiconductor spread on said pair of electrodes; and a catalyst layer coated on said gas detecting body, said layer being made of V and Mo supported by one catalyst carrier selected from the group consisting of Al 2 O 3 , SiO 2 , and SiO 2 -Al 2 O 3 , the amount of said V in said catalyst layer being limited from about 0.1 wt % to about 50 wt % and the atomic ratio (Mo/V) between said V and Mo being limited from about 0.05 to about 0.5.
Claim 5
Dependent Claim
21 words
A freon gas detecting element according to claim 1 or 2, wherein said detecting body is made of a ZnO-based semiconductor.
Claim 6
Dependent Claim
66 words
A freon gas detecting element according to claim 1 or 2, wherein said gas detecting body is made of a metal oxide semiconductor selected from the group consisting of ZnO, SnO 2 , Fe 2 O 3 , ZnO-Me 2 O 3 (Me=Sb or Cr), SnO 2 -Me 2 O 3 (Me=Sb or Cr), and Fe 2 O 3 -Me 2 O 3 (Me=Sb or Cr).
Claim 7
Dependent Claim
28 words
A freon gas detecting element according to claim 1 or 2, wherein said pair of electrodes is disposed on the outer periphery of a hollow cylindrical insulative body.
Claim 8
Dependent Claim
29 words
A freon gas detecting element according to claim 5, further including a heater detachably disposed in the hollow interior of said insulative body for heating said gas detecting body.
References Cited (Backward Citations)
US4045178A
Cited
US4259292A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |