Pressure sensor for sealed containers

• US 6,182,514 B1
• Filed: 07/15/1999
• Issued: 02/06/2001
• Est. Priority Date: 07/15/1999
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: UT-Battelle LLC
• Inventors: Hodges, Franklin R.
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): AW MUSSE, ABDULLAHI H
• Application Number:
  US09/353,908
• Time in Patent Office: 572 Days
• Field of Search: 737/22, 737/28, 737/03, 738/665, 737/291
• US Class Current: 73/722
• CPC Class Codes: G01L 19/086 for remote indication
• CPC Class Codes: G01L 9/0036 using variations in inductance
• CPC Class Codes: G01L 9/14 involving the displacement of magnets, e.g. electromagnets

Abstract

A magnetic pressure sensor for sensing a pressure change inside a sealed container. The sensor includes a sealed deformable vessel having a first end attachable to an interior surface of the sealed container, and a second end. A magnet mounted to the vessel second end defining a distance away from the container surface provides an externally detectable magnetic field. A pressure change inside the sealed container causes deformation of the vessel changing the distance of the magnet away from the container surface, and thus the detectable intensity of the magnetic field.

Claims

1. A pressure sensor suitable for detecting a pressure change inside a container, said sensor comprising:

a sealed deformable vessel disposed inside the container;

a deformation indicator mounted to said vessel which provides an indication of vessel deformation which is detectable external to the container; and

a detector disposed outside of the container, wherein a change in pressure inside the container deforms said vessel, and said detector detects the indication provided by said deformation indicator of the vessel deformation, wherein said deformation indicator is a magnet mounted to said vessel located at a distance away from an exterior surface of said container, and wherein a pressure change in said container causes deformation of said vessel changing said distance of said magnet away from said container surface.

2. The pressure sensor as in claim 1, wherein said deformable vessel has a convoluted bellows shape.

3. The pressure sensor as in claim 1, wherein said deformable vessel is formed from metal.

4. The magnetic pressure sensor as in claim 1, wherein said magnet is a permanent magnet.

5. The pressure sensor as in claim 1, wherein said magnet is a steady state rare earth magnet.

6. The pressure sensor as in claim 1, wherein said detector is a Teslameter.

7. The pressure sensor as in claim 1, wherein said detector is a magnetic switch.

8. The pressure sensor as in claim 7, further including an alarm device electrically connected to said switch.

9. The pressure sensor as in claim 1, wherein said detector is a second magnet.

10. The pressure sensor as in claim 9, further including an antenna disposed within the magnetic field of said second magnet, wherein said antenna rises with said second magnet.

11. The pressure sensor as in claim 10, further including a remote radio frequency transmitter and receiver which transmits radio waves toward said raised antenna and receives radio waves from said antenna.

12. The pressure sensor as in claim 1, further including a probe attached to said vessel, wherein said probe contacts an interior surface of said container when said vessel deforms.

13. The pressure sensor as in claim 12, wherein said detector determines whether the vessel is deformed by ultrasonically determining whether said probe is in contact with said container inner surface.

14. A pressure sensor suitable for detecting a pressure change inside a container, said sensor comprising:

a sealed deformable vessel disposed inside the container;

a deformation indicator mounted to said vessel which provides an indication of vessel deformation which is detectable external to the container;

a detector disposed outside of the container, wherein a change in pressure inside the container deforms said vessel, and said detector detects the indication provided by said deformation indicator of the vessel deformation; and

a location indicator disposed on the outside of said container proximal said vessel for indicating the approximate location of said vessel inside said container.

15. The pressure sensor as in claim 14, wherein said location indicator is a memory device containing information concerning contents of said container.

16. The pressure sensor as in claim 15, wherein said information includes atmospheric temperature and pressure when said container is sealed.

17. A magnetic pressure sensor comprising:

a sealed deformable vessel having a first end attachable to an interior surface of a container, and a second end which moves when said vessels deforms due to a pressure change in said vessel; and

a magnet having, a magnetic field detectable from outside of the container, said magnet being mounted to said vessel second end located at a distance away from said container surface, wherein a pressure change in said container causes deformation of said vessel changing said distance of said magnet away from said container surface and the intensity of the magnetic field detectable from outside of the container.

18. The magnetic pressure sensor as in claim 17, wherein said deformable vessel has a convoluted bellows shape.

19. The magnetic pressure sensor as in claim 17, wherein said deformable vessel is formed from metal.

20. The magnetic pressure sensor as in claim 17, wherein said magnet is a permanent magnet.

21. The magnetic pressure sensor as in claim 17, wherein said magnet is a steady state rare earth magnet.

22. The magnetic pressure sensor as in claim 17, further including a detector disposed within the magnetic field of said magnet for detecting a change in the magnetic field intensity caused by said vessel deformation.

23. The magnetic pressure sensor as in claim 22, wherein said detector is a Teslameter.

24. The magnetic pressure sensor as in claim 22, wherein said detector is a magnetic switch.

25. The magnetic pressure sensor as in claim 24, further including an alarm device electrically connected to said switch.

26. The magnetic pressure sensor as in claim 22, wherein said detector is a second magnet which reacts to a change in the magnetic field intensity of said magnet mounted to said vessel second end.

27. The magnetic pressure sensor as in claim 26, further including an antenna disposed within the magnetic field of said second antenna, wherein said antenna rises with said second magnet.

28. The pressure sensor as in claim 27, further including a remote radio frequency transmitter and receiver which transmits radio waves toward said raised antenna and receives radio waves from said raised antenna.