US4576781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature threshold detectors
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1982-07-02
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Granted: 1986-03-18
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Expires: 2002-07-02
Abstract
Abstract A threshold temperature is detected by providing a sensor (12) comprising a magnet (13) inside a ferromagnetic shield (14) which has a lower Curie point than that of the magnet. Below threshold the sensor is magnetically characterless. Above threshold the sensor displays a magnetic character which is detected at a solid-state magnetometer (16). In one application the sensor is located in a breeder fuel sub-assembly (20) at the breeder/fuel region (22) of a fast-fission nuclear reactor and the magnetometer is located in a fuel sub-assembly (21). In another application the sensor is located inside a sealed containment vessel and the magnetometer is located outside the vessel.
Inventors
- 👤 Edward Duncombe
- 👤 John P. Winstanley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:57
CPC Classifications
G; G01; G01K; G01K3/00; G01K7/00; G01K7/36; G01K7/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
71 words
A temperature threshold detector system comprising a threshold temperature sensor nd an independently locatable and physically separate detector displaced therefrom for detecting the output of said sensor wherein the sensor comprises a magnet inside a ferromagnetic shield having a lower Curie point than that of the magnet, the detector being responsive to a change in the field of the magnet as arises when the Curie point of the shield is exceeded.
Claim 2
Dependent Claim
71 words
A temperature threshold detector system comprising a threshold temperature sensor nd an independently locatable and physically separate detector displaced therefrom for detecting the output of said sensor wherein the sensor comprises a magnet inside a ferromagnetic shield having a lower Curie point than that of the magnet, the detector being responsive to a change in the field of the magnet as arises when the Curie point of the shield is exceeded.
Claim 3
Dependent Claim
14 words
A system as claimed in claim 1 wherein the detector is a fluxgate magnetometer.
Claim 4
Dependent Claim
32 words
A system as claimed in claim 1 wherein there is an array of sensors and each detector is responsive to the change in magnetic field of a respective adjacent pair of sensors.
Claim 5
Dependent Claim
41 words
A system as claimed in claim 3 wherein the sensors are disposed in respective breeder fuel sub-assemblies at the boundary region of a fast fission nuclear reactor and the detectors are located in fissile fuel sub-assemblies also at said boundary region.
Claim 6
Dependent Claim
24 words
A system as claimed in claim 1 wherein the sensor is located inside a containment vessel and the detector is located outside said vessel.
Claim 7
Dependent Claim
104 words
A temperature threshold detector system comprising a threshold temperature sensor for transmitting a wireless output indicative of the existence of a temperature threshold condition, an independently locatable and physically separate detector displaced therefrom and unconnected therewith for detecting the wireless output of said sensor, and means for connecting said detector with a monitoring station, said sensor comprising a permanent magnet having a first Curie point inside a ferromagnetic shield having a second Curie point lower than the first Curie point, said detector being responsive to a change in the field of the magnet as arises when the Curie point of the shield is exceeded.
Claim 8
Dependent Claim
104 words
A temperature threshold detector system comprising a threshold temperature sensor for transmitting a wireless output indicative of the existence of a temperature threshold condition, an independently locatable and physically separate detector displaced therefrom and unconnected therewith for detecting the wireless output of said sensor, and means for connecting said detector with a monitoring station, said sensor comprising a permanent magnet having a first Curie point inside a ferromagnetic shield having a second Curie point lower than the first Curie point, said detector being responsive to a change in the field of the magnet as arises when the Curie point of the shield is exceeded.
Claim 9
Dependent Claim
15 words
A system as claimed in claim 6 wherein the detector is a flux gate magnetometer.
Claim 10
Dependent Claim
32 words
A system as claimed in claim 6 wherein there is an array of sensors and each detector is responsive to the change in magnetic field of a respective adjacent pair of sensors.
Claim 11
Dependent Claim
41 words
A system as claimed in claim 8 wherein the sensors are disposed in respective breeder fuel sub-assemblies at the boundary region of a fast fission nuclear reactor and the detectors are located in fissile fuel sub-assemblies also at said boundary region.
Claim 12
Dependent Claim
24 words
A system as claimed in claim 6 wherein the sensor is located inside a containment vessel and the detector is located outside said vessel.
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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) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |