US4259292A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas detecting element
Assignee: Toshiba Corp
•
Filing: 1978-01-31
•
Granted: 1981-03-31
•
Expires: 1998-01-31
Abstract
Abstract A gas detecting element comprising a hollow cylindrical insulative body, a pair of electrodes provided on the outer periphery of the insulative body, a gas detecting body covering up the outer periphery of the insulative body and the electrodes, a catalyst layer made of a catalytic material and coated on said gas detecting body, thereby covering up the surface of said gas detecting body, and a heater disposed in the hollow of the insulative body. When the gas detecting element comes into contact with a gas, the surface resistance of the gas detecting body varies, thereby detecting the gas.
Inventors
- 👤 Noboru Ichinose
- 👤 Hideo Okuma
- 👤 Yuji Yokomizo
- 👤 Takashi Takahashi
- 👤 Mieko Nishihara
- 👤 Masaki Katsura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:09
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A gas detecting element comprising a hollow cylidrical insulative body, a pair of electrodes provided on the outer periphery of said insulative body, a gas detecting body made of a porous ZnO-based semiconductor and covering up the outer periphery of said insulative body and said electrodes, and a catalyst layer made of a catalytic material and coated on said gas detecting body, thereby covering up the surface of said gas detecting body.
Claim 2
Dependent Claim
72 words
A gas detecting element comprising a hollow cylidrical insulative body, a pair of electrodes provided on the outer periphery of said insulative body, a gas detecting body made of a porous ZnO-based semiconductor and covering up the outer periphery of said insulative body and said electrodes, and a catalyst layer made of a catalytic material and coated on said gas detecting body, thereby covering up the surface of said gas detecting body.
Claim 3
Dependent Claim
27 words
The gas detecting element according to claim 1, wherein a heater for heating said gas detecting body is detachably disposed in the hollow of said insulative body.
Claim 4
Dependent Claim
48 words
The gas detecting element according to claim 1, wherein said catalyst layer is comprised of a carrier selected from the group consisting of Al 2 O 3 , SiO 2 , ZrO 2 and a composite material of these oxides and an oxidizing catalyst carried by said carrier.
Claim 5
Dependent Claim
34 words
The gas detecting element according to claim 1, wherein said catalyst layer is made of a material selected from the group consisting of Pt, Pd, a chloride of Pt and a chloride of Pd.
Claim 6
Dependent Claim
57 words
The gas detecting element according to claim 1, wherein said catalyst layer is made of an oxidizing catalyst selected from the group consisting of Ag, Cu, Co, Ni, a chloride of any one of these metals, V 2 O 5 , MoO 3 , NiO, Cr 2 O 3 , MgO and Fe 2 O 3 .
Claim 7
Dependent Claim
137 words
The gas detecting element according to claim 1, wherein said gas detecting body is made of a ZnO-based semiconductor selected from the group consisting of ZnO-Me 2 O--Me' 2 O 3 (Me═Li, Na, K or Rb; Me'═Ga, B, In, Fe, Al or Cr), ZnO--MeO--Me' 2 O 3 (Me═Ca, Sr, Ba, Co, Ni or Mn; Me'═Ga, B, In, Fe, Al or Cr), ZnO--Me 2 O 3 -Me' 2 O 3 (Me═Sc, Y or La; Me'═Ga, B, In, Fe, Al or Cr), ZnO--MeO 2 --Me' 2 O 3 (Me═Ti, Zr, Hf, Sn or Ge; Me'═Ga, B, In, Fe, Al or Cr), ZnO--Me 2 O 5 --Me' 2 O 3 (Me═Nb, Ta, Sb or V; Me'═Ga, B, In, Fe, Al or Cr) or ZnO--MeO 3 --Me' 2 O 3 (Me═Mo, W or Te; Me'═Ga, B, In, Fe, Al or Cr).
Claim 8
Dependent Claim
39 words
The gas detecting element according to claim 1, wherein a partition layer is formed between said catalyst layer and said gas detecting body, thereby suppressing the diffusion of the catalyst in said catalyst layer into said gas detecting body.
Claim 9
Dependent Claim
16 words
The gas detecting element according to claim 7, wherein said partition layer is made of mullite.
Claim 10
Dependent Claim
87 words
A gas detecting element, comprising: a hollow cylindrical insulative body; a pair of electrodes provided on the outer periphery of said insulative body; a gas detecting body made of a porous ZnO-based semi-conductor which covers the outer periphery of said insulative body and said electrodes; a first catalyst layer consisting of a catalytic material deposited on said gas detecting body such that it covers said gas detecting body; and a second catalyst layer consisting of a different catalytic material deposited on and covering said first catalyst layer.
Claim 11
Dependent Claim
87 words
A gas detecting element, comprising: a hollow cylindrical insulative body; a pair of electrodes provided on the outer periphery of said insulative body; a gas detecting body made of a porous ZnO-based semi-conductor which covers the outer periphery of said insulative body and said electrodes; a first catalyst layer consisting of a catalytic material deposited on said gas detecting body such that it covers said gas detecting body; and a second catalyst layer consisting of a different catalytic material deposited on and covering said first catalyst layer.
References Cited (Backward Citations)
US3092799A
Cited
US3507145A
Cited
US3631436A
Cited
US4036592A
Cited
US3952567A
Cited
US3961248A
Cited
US3959764A
Cited
US3999947A
Cited
JPS5184291A
Cited
US4015230A
Cited
US4045178A
Cited
US4099922A
Cited
US4045177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |