US4140990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Probe for selectively detecting vapors, water vapor in particular
Assignee: US Philips Corp
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Filing: 1977-02-10
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Granted: 1979-02-20
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Expires: 1997-02-10
Abstract
Abstract A probe for selectively detecting a vapor component in a gaseous atmosphere in contact therewith. The probe includes a pair of measuring electrodes and a semiconductor layer which is coated with a dielectric layer. An auxiliary electrode is placed opposite the semiconductor layer so that the voltage can be varied and consequently the level of the average current can be adjusted. It is thereby possible to detect the concentration of a vapor component to be measured in the entire range and with the same sensitivity.
Inventors
- 👤 Jean Pompei Katz de Warrens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:49
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/128
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
141 words
A probe for selectively detecting at least one vapourous component in a gas in contact with the probe, the operation of the probe being based on variations in its electric impedance due to a reaction at an active surface of the probe under the influence of variations in the concentration of said component, said probe comprising, a substrate on which two measuring electrode layers are disposed, said two electrode layers being separated from one another and being adapted for connection to a voltage source, a layer of semiconductor material covering the two electrode layers and on top thereof a layer of dielectic material, at least a portion of the surface of said dielectric layer constituting said active surface, and a third electrode disposed opposite the semiconductor material layer and which is at least in contact with the layer of dielectric material.
Claim 2
Dependent Claim
141 words
A probe for selectively detecting at least one vapourous component in a gas in contact with the probe, the operation of the probe being based on variations in its electric impedance due to a reaction at an active surface of the probe under the influence of variations in the concentration of said component, said probe comprising, a substrate on which two measuring electrode layers are disposed, said two electrode layers being separated from one another and being adapted for connection to a voltage source, a layer of semiconductor material covering the two electrode layers and on top thereof a layer of dielectic material, at least a portion of the surface of said dielectric layer constituting said active surface, and a third electrode disposed opposite the semiconductor material layer and which is at least in contact with the layer of dielectric material.
Claim 3
Dependent Claim
60 words
A probe as claimed in claim 1, wherein the third electrode comprises one or more elongate elements, at least one of the elements of the third electrode being disposed substantially parallel with the direction of current lines which in operation will pass through the thin layer of semiconductor material from the one to the other of the two measuring electrodes.
Claim 4
Dependent Claim
35 words
A probe as claimed in claim 2 wherein said one element of the third electrode is at least as long as the minimum spacing, viewed perpendicularly, between the edges of said two first measuring electrodes.
Claim 5
Dependent Claim
32 words
A probe as claimed in claim 1 wherein the surface of the third electrode is at the most equal to half the common surface between the dielectric layer and the semiconductor layer.
Claim 6
Dependent Claim
25 words
A probe as claimed in claim 1 wherein the third electrode is disposed at the outer side on the dielectric layer opposite the semiconductor layer.
Claim 7
Dependent Claim
21 words
A probe as claimed in claim 1 wherein the third electrode is disposed between the dielectric layer and the semiconductor layer.
Claim 8
Dependent Claim
27 words
A probe as claimed in claim 1 wherein said semiconductor layer is comprised of stannic oxide, the dielectric layer comprises tetraethoxysilane and the third electrode comprises aluminum.
Claim 9
Dependent Claim
40 words
A probe as claimed in claim 1 wherein said two electrode layers comprise parallel elongate strip-shaped elements with the third electrode extending generally perpendicular thereto and said third electrode is adapted to be connected to a source of control voltage.
Claim 10
Dependent Claim
28 words
A probe as claimed in claim 1 wherein the layer of semiconductor material and the layer of dielectric material are formed on the substrate in an ionized environment.
Claim 11
Dependent Claim
142 words
A probe for selectively detecting at least one component of a gas in contact with the probe, the operation of the probe being based upon the variation of its electrical impedance due to a reaction at an active surface of the probe, said probe comprising, a dielectric substrate, a pair of spaced apart measuring electrodes disposed on the substrate and each having terminal means for connection to a voltage source, a layer of semiconductor material on said substrate and covering the measuring electrodes, a layer of dielectric material on top of the semiconductor layer, at least a part of the dielectric layer forming said active surface of the probe, and a third electrode disposed opposite the semiconductor layer and in contact with the layer of dielectric material for applying a control voltage thereto whereby the level of current flow can be adjusted.
Claim 12
Dependent Claim
142 words
A probe for selectively detecting at least one component of a gas in contact with the probe, the operation of the probe being based upon the variation of its electrical impedance due to a reaction at an active surface of the probe, said probe comprising, a dielectric substrate, a pair of spaced apart measuring electrodes disposed on the substrate and each having terminal means for connection to a voltage source, a layer of semiconductor material on said substrate and covering the measuring electrodes, a layer of dielectric material on top of the semiconductor layer, at least a part of the dielectric layer forming said active surface of the probe, and a third electrode disposed opposite the semiconductor layer and in contact with the layer of dielectric material for applying a control voltage thereto whereby the level of current flow can be adjusted.
Claim 13
Dependent Claim
26 words
A probe as claimed in claim 10 wherein the third electrode comprises a thin strip-shaped conductive element sandwiched between the semiconductor layer and the dielectric layer.
References Cited (Backward Citations)
US3223609A
Cited
US3954590A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |