Guided wave radar level gauge with improved sealing arrangement

摘要

A radar level gauge for determining a filling level of a product contained in a tank. The gauge has a sealing arrangement comprising a hollow housing, a conductor and a dielectric sleeve arranged inside the housing and surrounding the conductor. At least one gap is formed between the dielectric sleeve and an adjacent, electrically conducting surface, the gap having a first end which is open to an interior of the tank, so that in use, tank atmosphere may enter and condensate in the gap. The sealing arrangement further comprises an electrically conducting coating provided on a surface of the dielectric sleeve facing the gap, and in electrical contact with said adjacent, electrically conducting surface, so that an impedance between the electrically conducting coating and the adjacent electrically conducting surface is sufficiently low at an operating frequency of the gauge to reduce an influence of any medium present in the gap.

主权项

1. A guided wave radar level gauge for determining a filling level of a product contained in a tank, which level gauge comprises:
a transceiver for transmitting electromagnetic transmit signals and receiving electromagnetic echo signals reflected at a surface of said product, a probe, connected to said transceiver and configured to extend into said tank and to guide said transmit signals towards said surface and to guide said echo signals to said transceiver, a sealing arrangement comprising:
a hollow housing,a conductor extending inside said housing for transmitting electromagnetic signals between said transceiver and said probe,a dielectric sleeve arranged inside said housing and surrounding said conductor,at least one gap, formed between said dielectric sleeve and an adjacent, electrically conducting surface, said gap having an open end facing said tank, allowing tank atmosphere to enter and condensate in said gap, andan electrically conducting coating provided on a surface of said dielectric sleeve facing said gap, and in electrical contact with said adjacent, electrically conducting surface, so that an impedance between said electrically conducting coating and said adjacent electrically conducting surface is sufficiently low at an operating frequency of said gauge to reduce an influence of any medium present in said gap.