Single conductor probe radar level gauge system and tank arrangement

A tank arrangement comprising:

• a tank having a tubular mounting structure extending substantially vertically upwards from a roof of said tank, said tank containing a product to be gauged;
• and
• a radar level gauge system for determining a filling level of the product contained in said tank, said radar level gauge system comprising:
• a transceiver arranged outside said tank for generating, transmitting and receiving electromagnetic signals;
• a single conductor probe arranged inside said tank and electrically connected to said transceiver via a feed-through arranged at an upper end of said mounting structure, said single conductor probe extending substantially vertically through said mounting structure past a lower end of said mounting structure towards and into the product in the tank for guiding an electromagnetic transmit signal from said transceiver through a tank atmosphere towards a surface of the product, and for returning an electromagnetic surface reflection signal resulting from reflection of said transmit signal at said surface back towards said transceiver;
• an electrically conductive shielding structure radially spaced apart from said single conductor probe and extending along a top portion of said single conductor probe inside said mounting structure and past the lower end of said mounting structure;
• and
• processing circuitry connected to said transceiver for determining said filling level based on said transmit signal and said surface reflection signal,
• wherein said shielding structure at least partly encloses the top portion of said single conductor probe, and is open in a radial direction to allow entry of said product, thereby enabling measurement of filling levels corresponding to the top portion of the probe,
• said shielding structure comprising a first portion extending along said single conductor probe inside the mounting structure, and a second portion extending along said single conductor probe below the lower end of the mounting structure,
• wherein the shielding structure exhibits, in a cross-section perpendicular to an extension of said single conductor probe:
• a total enclosing arc angle around said single conductor probe greater than 180° in said first portion;
• and
• a total enclosing arc angle around said single conductor probe that decreases with increasing distance from the lower end of the mounting structure in said second portion.