Patent ID: 8763453

Claim:
An arrangement for measuring the fill level of a fill substance in a container, comprising: a fill level measuring device that works with microwaves, wherein the device includes measuring device electronics having a microwave generator for producing microwave signals, and an antenna connected to said measuring device electronics and serving to transmit the microwave signals into the container toward the fill substance and an antenna serving to receive reflection signals of the microwave signals reflected in the container back in the direction of said antenna; and at least one feedthrough installed in a signal path of the microwave signals, wherein said at least one feedthrough includes a hollow conductor, and a microwave transparent window installed gas tightly in said hollow conductor, wherein said window includes: a disk, whose thickness corresponds approximately to a half wavelength or a small integer multiple of the half wavelength of a first, hollow conductor propagation capable, signal mode, of the microwave signals at a predetermined signal frequency in said disk; and two matching layers located on oppositely lying, outer surfaces of said disk, wherein said matching layers' thickness corresponds approximately to a fourth of the wavelength of the first, hollow conductor propagation capable, signal mode of the microwave signals at the predetermined signal frequency in the matching layers; and said matching layers each have a dielectric constant, which corresponds to a square root of a product of a dielectric constant of said hollow conductor and a dielectric constant of said disk.