A test arrangement for a level gauge system comprising a measurement unit and a signal propagation device connected to the measurement unit, the test arrangement comprising: a waveguide being connectable to the level gauge system at a connection to allow an electromagnetic transmit signal transmitted by the measurement unit to be propagated by said waveguide; a first signal reflecting device arranged along said waveguide, at a first distance along said waveguide from said connection, said first signal reflecting device being configured to allow at least a portion of said electromagnetic transmit signal from the measurement unit to pass said first signal reflecting device and continue further along said waveguide; and a second signal reflecting device arranged along said waveguide, at a second distance along said waveguide from said connection being greater than said first distance, for reflecting an electromagnetic signal traveling along said waveguide from said first signal reflecting device back towards said first signal reflecting device, characterised in that, said first signal reflecting device is configured to either reflect an electromagnetic signal traveling along said waveguide from said second signal reflecting device back towards said second reflecting device or to allow an electromagnetic signal traveling along said waveguide from said second signal reflecting device towards said first signal reflecting device to pass said first signal reflecting device to allow said electromagnetic signal to be received by said measurement unit of the level gauge system, wherein said first signal reflecting device comprises switching circuitry controllable between a signal conducting state and a signal reflecting state, wherein said test arrangement further comprises timing control circuitry connected to said switching circuitry and to said waveguide between said connection and said switching circuitry, said timing control circuitry being configured to sense said electromagnetic transmit signal transmitted by the measurement unit and to control a switching state of said switching circuitry based on a timing of said electromagnetic transmit signal. a waveguide being connectable to the level gauge system at a connection to allow an electromagnetic transmit signal transmitted by the measurement unit to be propagated by said waveguide; a first signal reflecting device arranged along said waveguide, at a first distance along said waveguide from said connection, said first signal reflecting device being configured to allow at least a portion of said electromagnetic transmit signal from the measurement unit to pass said first signal reflecting device and continue further along said waveguide; and a second signal reflecting device arranged along said waveguide, at a second distance along said waveguide from said connection being greater than said first distance, for reflecting an electromagnetic signal traveling along said waveguide from said first signal reflecting device back towards said first signal reflecting device, characterised in that, said first signal reflecting device is configured to either reflect an electromagnetic signal traveling along said waveguide from said second signal reflecting device back towards said second reflecting device or to allow an electromagnetic signal traveling along said waveguide from said second signal reflecting device towards said first signal reflecting device to pass said first signal reflecting device to allow said electromagnetic signal to be received by said measurement unit of the level gauge system, wherein said first signal reflecting device comprises switching circuitry controllable between a signal conducting state and a signal reflecting state, wherein said test arrangement further comprises timing control circuitry connected to said switching circuitry and to said waveguide between said connection and said switching circuitry, said timing control circuitry being configured to sense said electromagnetic transmit signal transmitted by the measurement unit and to control a switching state of said switching circuitry based on a timing of said electromagnetic transmit signal.