| 摘要 |
<p>A guided wave radar level gauge (1) for determining a filling level of a product (3) contained in a tank (5). The gauge has a sealing arrangement (4) comprising a hollow housing (11), a conductor (13), and a dielectric sleeve (16) arranged inside the housing and surrounding the conductor. At least one gap (26, 27) 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 (29, 29a) 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. By short-circuiting the gap, any medium entering the gap between will not have any influence on the signal transmission properties.</p> |
