US3649891A
Expired / Lapsed
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Capacitive cryogenic thermometer
Assignee: Corning Glass Works
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Filing: 1970-06-18
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Granted: 1972-03-14
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Expires: 1990-06-18
Abstract
Abstract A capacitive device suitable for use in cryogenic temperature measuring. The dielectric material used in the capacitor is made from a composition in which strontium titanate, SrTiO3, has been controllably crystallized in a glass matrix. A capacitive device having this type of dielectric material is particularly useful in measuring cryogenic temperatures in that the dielectric constant of such a dielectric material decreases smoothly with decreasing temperature, varies linearly with temperature over a suitable portion of the range thereof, and possesses a large sensitivity in the cryogenic temperature range.
Inventors
- 👤 William N Lawless
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:52
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/04; G; G01; G01K; G01K7/00; G01K7/34; G01K7/343
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
25 words
The capacitive device of claim 1 wherein the dopants are selected from the group consisting of tantalum oxide, bismuth oxide, vanadium oxide and niobium oxide.
Claim 2
Dependent Claim
26 words
The capacitive device of claim 1 having more than two electrically conductive members, each said member being separated from adjacent members by one saId dielectric layer.
Claim 3
Dependent Claim
29 words
The capacitive device of claim 1 wherein said glass matrix consists of a glass selected from the group consisting of alumino-silicate glass, borate glass, phosphate glass and germanite glass.
Claim 4
Dependent Claim
14 words
The capacitive device of claim 1 wherein said strontium titanate is crystalized in situ.
Claim 5
Dependent Claim
123 words
A capacitive cryogenic thermometer comprising a plurality of electrically conductive members, a dielectric layer disposed between adjacent conductive members and being formed of material consisting of a glass matrix, 0 to 5 percent by weight of at least one dopant selected from the group consisting of tantalum oxide, bismuth oxide, vanadium oxide, and niobium oxide, and crystalline strontium titanate, said material being formed from a glass containing at least 50 percent by weight of strontium titanate from and within which glass at least a portion of said strontium titanate is crystallized by heat treatment of said glass, and terminal means connected to said members, the capacitance of said thermometer being a function of temperature whereby temperature is determined by measuring the capacitance thereof.
Claim 6
Dependent Claim
13 words
The thermometer of claim 6 wherein said glass matrix consists of alumino-silicate glass.
Claim 7
Dependent Claim
13 words
The thermometer of claim 7 wherein said strontium titanate is crystallized in situ.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |