Patent ID: 6859187

Claim:
A horn antenna intended for transmission and reception of microwaves when gauging a level of a surface of a medium stored in a tank by means of a microwave unit arranged at the roof of the tank, where the antenna comprises: a first conductive housing ( 7 ) having a wave guide port ( 8 ), which is connectable to a wave guide, a first aperture ( 10 ), which is separated from the wave guide port ( 8 ) and a first divergent section between the wave guide port ( 8 ) and the first aperture ( 10 ); a dielectric body ( 11 ) is, for maintaining a mechanically pressure resistant antenna design, arranged inside and essentially filling the first conductive housing ( 7 ), which body ( 11 ) displays a free end ( 12 ) in the area of the first aperture ( 10 ), characterized in that around the first aperture ( 10 ) is arranged a locking device ( 13 ), the locking device ( 13 ) is arranged to fix the dielectric body ( 11 ) in the first housing ( 7 ), and in the area of the locking device ( 13 ) is, for efficiently separating atmospheres inside and outside the tank, arranged at least one flexible pressure sealing element ( 16 ) between the dielectric body ( 11 ) and the first housing ( 7 ).