US4313907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the detection of a combustible gas
Assignee: Industrial Scientific Corp
•
Filing: 1980-04-21
•
Granted: 1982-02-02
•
Expires: 2000-04-21
Abstract
Abstract An improvement is provided in apparatus used to detect combustible gases, which embodies a Wheatstone bridge circuit including a refractory-coated detector element having thereon a catalyst for promoting oxidation of the combustible gas to be detected constituting one leg of the bridge and a refractory-coated reference element constituting a second leg of the bridge. The improvement, in its broadest aspect, consists in using a mixture of palladium, palladium oxide and nickel oxide as the catalyst on the detector element. In addition, an improved reference element is provided which has a coating of either sodium metasilicate or lead borate deposited thereon.
Inventors
- 👤 Frank X. McNally
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:36
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide.
Claim 2
Dependent Claim
122 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide.
Claim 3
Dependent Claim
136 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide; and a reference element having a coating of a sodium metalsilicate glass deposited thereon.
Claim 4
Dependent Claim
136 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide; and a reference element having a coating of a sodium metalsilicate glass deposited thereon.
Claim 5
Dependent Claim
136 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide; and a reference element having a coating of a lead borate glass deposited thereon.
Claim 6
Dependent Claim
136 words
In an apparatus for detecting a combustible gas which comprises a Wheatstone bridge circuit having (a) a detector element comprising an electrically conducting member coated with a refractory and having on the surface of said refractory a catalyst for the oxidation of said gas, said detector element constituting one leg of said bridge, and (b) a reference element comprising an electrically conducting member coated with a refractory, said reference element constituting a second leg of said bridge, whereby upon catalytic oxidation of said gas an electrical signal approximately proportional to the amount of said gas present at the detector element is produced, the Improvement which comprises, a detector element having as said catalyst a composition containing palladium, palladium oxide and nickel oxide; and a reference element having a coating of a lead borate glass deposited thereon.
Claim 7
Dependent Claim
23 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing palladium, palladium oxide and nickel oxide.
Claim 8
Dependent Claim
23 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing palladium, palladium oxide and nickel oxide.
Claim 9
Dependent Claim
21 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing a sodium metasilicate glass.
Claim 10
Dependent Claim
21 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing a sodium metasilicate glass.
Claim 11
Dependent Claim
21 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing a lead borate glass.
Claim 12
Dependent Claim
21 words
A resistance element comprising a platinum coil coated with alumina on which is deposited a coating containing a lead borate glass.
References Cited (Backward Citations)
US2805134A
Cited
US2904406A
Cited
US3200011A
Cited
US4072467A
Cited
US4045177A
Cited
US4193964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |