Patent US3848466A successfully refreshed from Google Patents.
US3848466A
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US
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Magnetic temperature sensor
Assignee: United States Atomic Energy Commission
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Filing: 1974-01-30
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Granted: 1974-11-19
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Expires: 1994-01-30
Abstract
Abstract A sensor for determining rapid temperature changes at the surface of nonmagnetic structures. A thin layer of a material of sufficiently high magnetic permeability and Curie temperature is bonded to the surface to be monitored and a magnetic field is induced in the layer. A sensing coil detects changes in the permeability of the magnetic material layer via changes in impedance and/or phase shift as a function of the layer temperature.
Inventors
- 👤 R Dial
- 👤 J Keyes
- 👤 J Krewson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:54
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/36; G01K7/38; G01K13/00; G01K13/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
A temperature sensor for monitoring the temperature and detecting rapid temperature changes of one surface of a wall of nonmagnetic material comprising: a layer of ferromagnetic material disposed in contact with said one surface of said wall; at least one electromagnetic coil disposed on the other surface of said wall opposite said one surface from said layer; an electrical signal source connected to said coil for inducing magnetic fields in said layer, and means responsive to the changes in current induced in said coil from changes of the magnetic permeability of said layer with changes in temperature of said one surface for indicating the temperature of said one surface.
Claim 2
Dependent Claim
109 words
A temperature sensor for monitoring the temperature and detecting rapid temperature changes of one surface of a wall of nonmagnetic material comprising: a layer of ferromagnetic material disposed in contact with said one surface of said wall; at least one electromagnetic coil disposed on the other surface of said wall opposite said one surface from said layer; an electrical signal source connected to said coil for inducing magnetic fields in said layer, and means responsive to the changes in current induced in said coil from changes of the magnetic permeability of said layer with changes in temperature of said one surface for indicating the temperature of said one surface.
Claim 3
Dependent Claim
125 words
The temperature sensor as set forth in claim 1 wherein said at least one coil includes a pair of bifilar wound coils, wherein said electrical signal source is a variable oscillator connected to a first coil of said pair of coils, and wherein said means for indicating the temperature of said one surface includes a phase detector having a first input connected to the output of said oscillator, a second input connected to the other coil of said pair of coils and an output for providing a signal whose amplitude is indicative of the phase difference between the signal at the output of said oscillator and the signal induced in said other coil corresponding to the magnetic permeability of said layer at a specific temperature.
Claim 4
Dependent Claim
51 words
The temperature sensor as set forth in claim 2 wherein said one surface is a containment surface for a corrosive fluid and wherein said layer is formed of a ferromagnetic material compatible with said corrosive fluid and has a Curie temperature greater than the upper range of temperature to be measured.
Claim 5
Dependent Claim
44 words
The temperature sensor as set forth in claim 2 wherein the temperature of said one surface to be monitored is in the range of from about 100* to 1,400*F and said layer of ferromagnetic material is iron having a Curie temperature of about 1,400*F.
Claim 6
Dependent Claim
55 words
The temperature sensor as set forth in claim 4 wherein said variable oscillator is set at a frequency to produce a substantially linear change in phase displacement between the oscillator output signal and the signal induced in said other coil for changes in temperature of said layer within the range of temperatures to be monitored.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |