Device for determining and / or monitoring the flow of a medium through a pipeline

The invention relates to a device for determining and / or monitoring the volume and / or mass flow of a medium (3) that flows through a pipeline (2) in a flow direction, wherein in the pipe wall (4) of the pipeline (2) incidence / Ausstrahloffnungen (5a, 5b) are provided for the ultrasonic measuring signals of ultrasonic sensors (6a, 6b) which are disposed in close proximity to each other, are sent or received, wherein a sound conductor (8) in the region of the outer wall of the pipe (2 ) is provided, via which switch the ultrasonic measuring signals to the input / Ausstrahloffnungen (5a, 5b) guided in the pipe (2) and (in such a way into the pipe line 2) and (from the pipe 2) to be coupled, that they pass through the pipeline (2) along a defined sound track, and with a control / evaluation unit (9) that the volume and / or mass flow of the medium (3) in the pipeline (2) based on the duration of the ultrasonic Mes ssignale determined by a sound entrainment method.