Radar level gauge system with modular propagation device

A radar level gauge system for determining the filling level of a product in a tank, comprising:

• a transceiver for generating, transmitting and receiving electromagnetic signals;
• an elongated propagation device connected to said transceiver for propagating an electromagnetic transmit signal in a longitudinal direction of said propagation device towards a surface of the product and for returning an electromagnetic reflection signal resulting from reflection of the electromagnetic transmit signal at the surface back towards said transceiver;
• and
• processing circuitry coupled to said transceiver for determining said filling level based on a relation between said transmit signal and said reflection signal,
• wherein said propagation device comprises:
• a first propagation device part comprising a cuff portion;
• and
• a second propagation device part comprising an end portion inserted in said cuff portion of the first propagation device part and joined together with said cuff portion by at least a first fastening arrangement,
• wherein said first fastening arrangement comprises:
• a tab formed in one of said cuff portion of the first propagation device part and said end portion of the second propagation device part;
• and
• a recess formed in the other one of said cuff portion of the first propagation device part and said end portion of the second propagation device part,
• said tab being received by said recess to interact with said recess to prevent relative movement between the first propagation device part and the second propagation device part at least in said longitudinal direction.