Abstract: The invention provides a level detection device (32) having a tube (34) which, in use, contains a material (14) for which its level in the tube (34) is to be measured. An ultrasonic transducer (10) is provided at one end of tube (34) for emitting an acoustic waveform that reflects off the surface of the level and returns to the ultrasonic transducer (10) to allow computation of the level from the time periods of the emitted and reflected acoustic waveforms. A flared section (22) within tube (34) diverges from adjacent ultrasonic transducer (10) towards the inside wall of tube (34) above the level, whereby, in use, the measured reflected waveform has substantially reduced signal distortion due to flare (22).