Ultrasonic fluid measuring arrangement with at least two waveguide parts spaced apart on an outer wall of a measuring tube

A fluid measuring means having a measuring tube, in which a circumferentially closed flow channel for a fluid to be measured is formed and in which at least two areas of an outer wall of the measuring tube are configured as waveguide parts, which each form a waveguide for surface acoustic waves,

• wherein a first and/or a second signal converter is arranged at each waveguide part and the first and/or the second signal converter is designed to excite surface acoustic waves in the respective waveguide part and/or to receive surface acoustic waves from the waveguide part, wherein surface acoustic waves emitted by the first and/or the second signal converter are adapted to be decoupled from the waveguide part and to propagate as bulk acoustic waves through the fluid in the flow channel and/or bulk acoustic waves are adapted to be coupled into the waveguide part and to be received by the first and/or the second signal converter, wherein the waveguide parts are spaced apart from each other along a circumference of the flow channel, and wherein at least two first signal converters arranged on different waveguide parts or two second signal converters arranged on different waveguide parts are spaced with respect to each other in an axial direction of the flow channel,
• wherein each of the waveguide parts are located opposite an area of the measuring tube which is not configured as a respective waveguide part and on which no signal converters are provided, wherein a wall thickness of the outer wall of the measuring tube in these areas is unchanged compared to areas of the outer wall adjacent in a circumferential direction, wherein the fluid measuring means is designed such that a decoupled bulk sound wave is reflected back at an area of an inner side to the waveguide part from which it was decoupled.