Ultrasound flow measurement device with signal quality monitoring

An ultrasound flow measurement device, comprising:

• a vessel through which a fluid to be measured is able to flow;
• an ultrasound measurement configuration with at least one ultrasound transducer for measuring a propagation time of an ultrasound signal having a plurality of periods along a measurement section running at least partly in a direction of flow;
• a controller for determining a fluid flow on a basis of the propagation time measured, wherein said controller containing:
• a memory;
• a signal generator configured to generate the ultrasound signal with a marker for determining the propagation time;
• a first evaluator for determining a period duration of at least one of the periods of the ultrasound signal received after passing through the measurement section;
• a digitizer for digitizing the ultrasound signal, an output of said digitizer is connected to an input of said first evaluator;
• a second evaluator for determining a spread value of a predetermined number of last received ultrasound signals, wherein when using a period duration modification as the marker, said second evaluator is configured to exclude the periods of a received ultrasound signal that contains the marker when determining the spread value;
• a third evaluator, the marker being detectable by said third evaluator;
• a comparator for comparing the spread value with at least one threshold value;
• and
• an actioning device for initiating a control action, assigned to the at least one threshold value that has been exceeded, for the ultrasound flow measurement device.