Patent US3938385A successfully refreshed from Google Patents.
US3938385A
Expired / Lapsed
US
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Distributed temperature sensor
Assignee: United States Department of the Navy
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Filing: 1974-05-24
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Granted: 1976-02-17
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Expires: 1994-05-24
Abstract
Abstract A distributed temperature sensor, in the form of a coaxial cable terminated in its characteristic impedance, comprising: an inner metallic conductor; a cylindrical, flexible, nonconductive material, surrounding the metallic conductor, having a plurality of axial voids extending throughout the length of the cable; a temperature-sensitive dielectric filling the axial voids, the voids being plugged at each end; an outer conductor surrounding the nonconductive material; and an optional elastomeric jacket surrounding the outer conductor. The invention also relates to apparatus for taking a continuous readout of a distributed temperature field, using the coaxial cable as a key element.
Inventors
- 👤 Tibor G. Horwath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:29
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/32; G01K1/00; G01K1/02; G01K1/026; G01K13/00; G01K7/00; G01K7/34; G01K7/343; G01K7/16; G01K2007/166
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
65 words
A distributed temperature sensor, in the form of a coaxial cable, comprising: a central, metallic, conductor; a cylindrical, flexible, nonconductive, material, surrounding the material, comprising: a plastic foam isolator, having voids randomly interspersed throughout its volume; and a liquid dielectric having a high ratio of dielectric constant to change in temperature, filling the voids of the isolator; and an outer conductor surrounding the nonconductive material.
Claim 2
Dependent Claim
65 words
A distributed temperature sensor, in the form of a coaxial cable, comprising: a central, metallic, conductor; a cylindrical, flexible, nonconductive, material, surrounding the material, comprising: a plastic foam isolator, having voids randomly interspersed throughout its volume; and a liquid dielectric having a high ratio of dielectric constant to change in temperature, filling the voids of the isolator; and an outer conductor surrounding the nonconductive material.
Claim 3
Dependent Claim
17 words
The distributed temperature sensor according to claim 1, further comprising: an elastomeric jacket surrounding the outer conductor.
Claim 4
Dependent Claim
21 words
The distributed temperature sensor according to claim 2, wherein the foam isolator is polyethylene; and the liquid dielectric is distilled water.
Claim 5
Dependent Claim
131 words
Method for taking a continuous readout of a distributed temperature field, such as the temperature profile of the ocean, comprising the steps of: terminating the coaxial cable having a configuration according to claim 1 in its characteristic impedance; connecting a time-domain reflectometer to the interminated end of the coaxial cable; connecting a display means to the output of the reflectometer; trolling the unconnected end of the coaxial cable in a medium whose temperature profile it is desired to obtain; energizing the time-domain reflectometer so that it sends pulses intermittently along the cable; energizing the display means so that it displays the output of the reflectometer; with the result that the reflected signals from the cable are displayed on the display means as a function of the temperature profile along the cable.
Claim 6
Dependent Claim
14 words
The method according to claim 4, wherein the display means is a cathode-ray tube.
Claim 7
Dependent Claim
15 words
The method according to claim 4, wherein the display means is a pen chart recorder.
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) | 1979-02-16 | 1979-08-18 | 1980-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-16 | 1983-08-18 | 1984-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-16 | 1987-08-18 | 1988-02-17 | $7700.00 | Window Closed / Lapsed |