Device for determining and monitoring the level of a medium in a container

• US 20090212996A1
• Filed: 04/27/2006
• Published: 08/27/2009
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Chen, Qi, Bergmann, Eric, Feisst, Klaus
• Granted Patent: US 7,864,104 B2
• Time in Patent Office: Days
• US Class Current: 342/124
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: H01Q 13/02 Waveguide horns

Abstract

The invention relates to an apparatus (1) for ascertaining and monitoring fill level (2) of a medium (3) in a container (4) by means of a travel-time measuring method of high-frequency measurement signals (6) with a horn antenna (7) having a waveguide section (8), a flared, horn section (9) and a cavity (11) filled, at least partially, with a dielectric filling body (12). Object of the invention is to provide a simple, temperature-stable, horn antenna filled with a dielectric material.

Claims

1-12. -12. (canceled)

13. An apparatus for ascertaining and monitoring the fill level of a medium in a container by means of a travel-time measuring method of high-frequency measuring signals, comprising:

a horn antenna having a waveguide section, a flared, horn section, and a cavity filled, at least partially, with a dielectric filling body, wherein;

a defined separation is provided in said flared, horn section between the inner surface of said horn antenna and the outer surface of said dielectric filling body for compensating different thermal expansions of said dielectric filling body and said horn antenna.

14. The apparatus as claimed in claim 13, wherein:

by said defined separation, a gap of 0.2-2 mm is formed between the inner surface of said horn antenna and the outer surface of said dielectric filling body.

15. The apparatus as claimed in claim 13, wherein:

said defined separation between the inner surface of said horn antenna and the outer surface of said dielectric filling body is constant.

16. The apparatus as claimed in claim 13, wherein:

said defined separation is interrupted periodically, or arbitrarily, so that the at least one ridge or at least one surface structure is formed on the outer surface of said filling body and/or on the inner surface of said horn antenna adjoining one another or separated from one another.

17. The apparatus as claimed in claim 13, wherein:

said filling body lies against said horn antenna over a certain length process-side for supporting and compensating process pressure forces on said filling body and/or said horn antenna.

18. The apparatus as claimed in claim 13, further comprising:

an attenuating foil absorbing the high-frequency measuring signal in said defined separation between the inner surface of the horn antenna and the outer surface of said dielectric filling body.

19. The apparatus as claimed in claim 13, further comprising:

at least one sealing element and/or at least one locking element between said filling body and said horn antenna for performing a sealing function and, simultaneously, a locking of said filling body in said horn antenna.

20. The apparatus as claimed in claim 19, wherein:

said sealing element and/or said locking element are/is placed in said waveguide section between said horn antenna and said filling body.

21. The apparatus as claimed in claim 13, wherein:

a disk-shaped widening is formed on the end of said filling body facing the process space.

22. The apparatus as claimed in claim 21, wherein:

a shape transition of said filling body from said flared horn section to said disk-shaped widening is continuously rounded, for preventing a notch effect in said filling body in the region of said shape transition.

23. The apparatus as claimed in claim 13, wherein:

said filling body and/or said horn antenna are/is multi-piece and/or they/it are/is formed of a plurality of different materials.

24. The apparatus as claimed in claim 13, wherein:

said filling body has in the radiation direction one of;

a convex, concave, conical or Fresnel lens shape.