Patent US4576781A successfully refreshed from Google Patents.
US4576781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature threshold detectors
Assignee: United Kingdom Atomic Energy Authority
•
Filing: 1982-07-02
•
Granted: 1986-03-18
•
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 12:17
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.
References Cited (Backward Citations)
US2460773A
Cited
US2615973A
Cited
US3087886A
Cited
US3564401A
Cited
DE2062901A1
Cited
GB1271260A
Cited
GB1369658A
Cited
DE2117137A1
Cited
US3950993A
Cited
US3976540A
Cited
DE2658203A1
Cited
US4304632A
Cited
US4371272A
Cited
US4405558A
Cited
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 |