Ultrasonic flowmeter

An ultrasonic flowmeter for measuring the flow of a medium flowing through a measuring tube using the travel time difference principle, the flowmeter comprising:

• a measuring tube having a measuring tube axis and a measuring tube wall configured to guide the medium, the measuring tube including a pair of housings extending to an outer side of the measuring tube wall;
• a pair of ultrasonic transducers, each transducer including a circumferential surface, a transducing element adapted to generate and/or sense ultrasonic pulses, and a transducer body having a second longitudinal axis and containing the transducing element, wherein the ultrasonic pulses are transmitted between the pair of transducers along a path, wherein at least one subpath of a path extending between said pair of transducers is non-parallel to the measuring tube axis;
• and
• an electronic circuit configured to operate the ultrasonic transducers and to evaluate sensed ultrasonic pulses from the transducers,
• wherein each of the pair of housings is configured to house one of the pair of transducers therein, wherein each housing includes an inner surface, a first longitudinal axis and an inner first diameter orthogonal to the first longitudinal axis, and wherein each housing at least partially surrounds the circumferential surface of the corresponding transducer disposed therein,
• wherein each transducer includes an end face exposable to a medium, the end face configured to transmitting the ultrasonic pulses between the transducing element and the medium and vice versa, and wherein a first sector of the transducer including the end face has a second diameter orthogonal to the second longitudinal axis,
• wherein each transducer includes a first protrusion protruding from the circumferential surface into a gap between the transducer body and the corresponding housing, wherein a height of the first protrusion is smaller than a width of the gap, and/or
• wherein each housing includes a second protrusion protruding into the gap opposite the circumferential surface of the corresponding transducer, wherein a height of the second protrusion is smaller than the width of the gap.