Method for operating a measuring device and measuring device for determining a fluid quantity

A measuring device for determining a fluid quantity relating to at least one of a fluid or a flow of the fluid, the measuring device comprising:

• a measuring tube at least one of receiving the fluid or conducting the fluid flow therethrough;
• first and second oscillation transducers disposed at a distance from one another along said measuring tube and defining a propagation path therebetween including only components of the measuring device;
• and
• a control device for driving said first and second oscillation transducers and evaluating measurement data recorded by said first and second oscillation transducers, said control device being adapted for:
• recording a first time of flight after which an ultrasound signal excited by said first oscillation transducer, after being conducted along said propagation path to said second oscillation transducer, is recorded at said second oscillation transducer;
• recording a second time of flight after which an ultrasound signal excited by said second oscillation transducer, after being conducted along said propagation path to said first oscillation transducer, is recorded at said first oscillation transducer;
• subsequently checking for a fulfillment of a report condition, said fulfilment depending on a time-of-flight difference between said first and second times of flight;
• and
• upon said report condition being fulfilled, at least one of outputting a report to a user or sending a report message to an external device or adapting at least one correction parameter used in determining the fluid quantity.