US4482882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture sensor with valve metal composition electrodes
Assignee: GENERAL EASTERN INSTRUMENTS Inc
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Filing: 1982-11-30
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Granted: 1984-11-13
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Expires: 2002-11-30
Abstract
Abstract A moisture sensor comprises a moisture-sensitive layer formed from the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate. Between the substrate and the moisture-sensitive tantalum oxide layer there is a base electrode of an anodically oxidizable metal, preferably tantalum, of a density higher than the density of the low density tantalum from which the tantalum oxide layer is formed. A covering electrode partially covering the tantalum oxide layer has windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer. The inactive regions of the tantalum oxide layer disposed below the windows are removed to increase the rate of response.
Inventors
- 👤 Ernst Luder
- 👤 Traugott Kallfass
- 👤 Christian Borgwardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:22
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01N27/225; G01N27/04; G01N27/12; G01N27/121
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
79 words
A moisture sensor comprising a thin layer of the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate and at least one base electrode disposed between the substrate and said tantalum oxide layer, wherein the base electrode disposed between the substrate and said tantalum oxide layer comprises a thin layer of valve metal of a density higher than the density of the highly resistive low density tantalum from which said tantalum oxide layer has been formed.
Claim 2
Dependent Claim
79 words
A moisture sensor comprising a thin layer of the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate and at least one base electrode disposed between the substrate and said tantalum oxide layer, wherein the base electrode disposed between the substrate and said tantalum oxide layer comprises a thin layer of valve metal of a density higher than the density of the highly resistive low density tantalum from which said tantalum oxide layer has been formed.
Claim 3
Dependent Claim
13 words
Moisture sensor according to claim 1 wherein the base electrode consists of tantalum.
Claim 4
Dependent Claim
33 words
Moisture sensor according to claim 2 wherein the electrode is formed of a thin layer that is selected from the group consisting of tantalum of the α- and β-modification applied on the substrate.
Claim 5
Dependent Claim
42 words
Moisture sensor according to claim 2 wherein the base electrode is formed of a thin layer of low density tantalum having a density substantially higher than the density of the low density tantalum of which the moisture-sensitive tantalum oxide layer is formed.
Claim 6
Dependent Claim
28 words
Moisture sensor according to claim 4 wherein the density of the low density tantalum forming the base electrode continuously decreases from the substrate toward the tantalum oxide layer.
Claim 7
Dependent Claim
13 words
Moisture sensor according to claim 1 wherein the base electrode consists of aluminum.
Claim 8
Dependent Claim
20 words
Moisture sensor according to claim 1 wherein the base electrode is selected from the group consisting of niobium and hafnium.
Claim 9
Dependent Claim
20 words
Moisture sensor according to claim 1 wherein the metal of the base electrode is oxidized through part of its thickness.
Claim 10
Dependent Claim
49 words
Moisture sensor according to claim 1 comprising a covering electrode partially covering the tantalum oxide layer and having windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer, the inactive regions of the tantalum oxide layer disposed below the said windows being removed.
Claim 11
Dependent Claim
21 words
Moisture sensor according to claim 9 wherein the inactive regions of the tantalum oxide layer have been removed by plasma etching.
Claim 12
Dependent Claim
25 words
Moisture sensor according to claim 9 wherein the base electrode and the covering electrode are in overlapping relationship with the tantalum oxide layer interposed therebetween.
Claim 13
Dependent Claim
71 words
Moisture sensor according to claim 1 wherein the structure formed by the base electrode and the tantalum oxide layer covering same has the shape of a first comb with teeth joined at one end by a web, and the covering electrode has the shape of a second comb whose teeth overlap the interstices between the teeth of the first comb and the marginal regions of the teeth of the first comb.
References Cited (Backward Citations)
GB1577724A
Cited
US4217623A
Cited
US4358748A
Cited
US4433319A
Cited
US4393434A
Cited
JPS6146222A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |