US5082789A
Expired / Lapsed
US
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Bismuth molybdate gas sensor
Assignee: Simon Fraser University
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Filing: 1988-08-23
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Granted: 1992-01-21
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Expires: 2008-08-23
Abstract
Abstract A bismuth molybdate gas sensor which provides stable sensitivity to gases such as alcohol, ketones, alkenes, and long chain alkanes is disclosed. Sensors comprising a mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate; or, bismuth iron molybdate are particularly effective. The bismuth molybdate mixture; or, the bismuth iron molybdate may be deposited as a thin film on a substrate or may take the form of a sintered powder.
Inventors
- 👤 Stanley R. Morrison
- 👤 Norma J. Hykaway
- 👤 William M. Sears
- 👤 Robert F. Frindt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:47
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833; Y10T436/203332; Y10T436/204165; Y10T436/21; Y10T436/214; Y10T436/216; Y10T436/22
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
64 words
A gas sensor, comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to a selected gas.
Claim 2
Dependent Claim
64 words
A gas sensor, comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to a selected gas.
Claim 3
Dependent Claim
41 words
A gas sensor, comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to a selected gas.
Claim 4
Dependent Claim
41 words
A gas sensor, comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to a selected gas.
Claim 5
Dependent Claim
28 words
A gas sensor as defined in claim 2, wherein said bismuth iron molybdate is doped with a metal selected from the group consisting of platinum, silver and palladium.
Claim 6
Dependent Claim
65 words
An alcohol gas sensor, comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to a selected gas.
Claim 7
Dependent Claim
65 words
An alcohol gas sensor, comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to a selected gas.
Claim 8
Dependent Claim
42 words
An alcohol gas sensor, comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to a selected gas.
Claim 9
Dependent Claim
42 words
An alcohol gas sensor, comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to a selected gas.
Claim 10
Dependent Claim
30 words
An alcohol gas sensor as defined in claim 5, wherein said bismuth iron molybdate is doped with a noble metal selected from the group consisting of platimun, silver and palladium.
Claim 11
Dependent Claim
91 words
A gas sensor for detecting, in a selected gas, the presence of a gas selected from the group consisting of alcohols, ketones, alkenes, and long chain alkanes, said gas sensor comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to said selected gas.
Claim 12
Dependent Claim
91 words
A gas sensor for detecting, in a selected gas, the presence of a gas selected from the group consisting of alcohols, ketones, alkenes, and long chain alkanes, said gas sensor comprising: (a) a substrate; (b) a film mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate deposited on said substrate; and, (c) means for electrically coupling said thin film to a monitor circuit for monitoring the electrical resistivity of said thin film during exposure of said thin film to said selected gas.
Claim 13
Dependent Claim
68 words
A gas sensor for detecting, in a selected gas, the presence of a gas selected from the group consisting of alcohols, ketones, alkenes, and long chain alkanes, said gas sensor comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to said selected gas.
Claim 14
Dependent Claim
68 words
A gas sensor for detecting, in a selected gas, the presence of a gas selected from the group consisting of alcohols, ketones, alkenes, and long chain alkanes, said gas sensor comprising: (a) a film composition of bismuth iron molybdate; and, (b) means for electrically coupling said composition to a monitor circuit for monitoring the electrical resistivity of said composition during exposure of said composition to said selected gas.
Claim 15
Dependent Claim
28 words
A gas sensor as defined in claim 8, wherein said bismuth iron molybdate is doped with a metal selected from the group consisting of platinum, silver and palladium.
Claim 16
Independent Claim
46 words
A method of measuring gas concentration, comprising the steps of: (a) exposing said gas to a sensor comprising a mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate; and (b) measuring the electrical resistance of said sensor.
Claim 17
Independent Claim
46 words
A method of measuring gas concentration, comprising the steps of: (a) exposing said gas to a sensor comprising a mixture of the Bi 2 Mo 3 O 12 and Bi 2 MoO 6 phases of bismuth molybdate; and (b) measuring the electrical resistance of said sensor.
Claim 18
Dependent Claim
21 words
A method as defined in claim 10 further comprising heating said sensor to an operating temperature of about 340 degrees celsius.
Claim 19
Independent Claim
30 words
A method of measuring gas concentration, comprising the steps of: (a) exposing said gas to a sensor comprising bismuth iron molybdate; and (b) measuring the electrical resistance of said sensor.
Claim 20
Independent Claim
30 words
A method of measuring gas concentration, comprising the steps of: (a) exposing said gas to a sensor comprising bismuth iron molybdate; and (b) measuring the electrical resistance of said sensor.
Claim 21
Dependent Claim
21 words
A method as defined in claim 12 further comprising heating said sensor to an operating temperature of about 340 degrees celsius.
References Cited (Backward Citations)
US4587104A
Cited
US4668635A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-20 | 1995-07-22 | 1996-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-20 | 1999-07-22 | 2000-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-20 | 2003-07-22 | 2004-01-21 | $7700.00 | Window Closed / Lapsed |