Abstract: A method operates a measuring device used to determine a fluid variable. The measuring devices contains a vibration transducer driven to excite a wave in the fluid due to a test excitation signal. The wave is guided along a propagation path back to the vibration transducer or to an additional vibration transducer, thereby exciting the (additional) vibration transducer to vibrate. An output signal relating to this vibration is acquired, and a frequency of that segment of the output signal that lies in an analysis interval is determined. The analysis interval starts once the driving of the vibration transducer to excite the wave has finished, and/or once a maximum of the amplitude of the vibration is reached. The determination of the fluid variable is performed based on the determined frequency. An error message or a notification is output to a user and/or to a device external to the measuring device.

Abstract: A method determines a measured quantity relating to the flow of a fluid through a measuring tube, in two propagation directions, and a receive signal is captured. A transit time difference is determined depending on the position of the main maximum of a cross-correlation of the receive signals. Whereupon the measured quantity is determined depending on the transit time difference, and the transmitting ultrasonic transducer is controlled in each case with an excitation signal. The excitation signal has a fixed carrier frequency. The excitation signal has a phase shift and/or an envelope with a plurality of temporally spaced maxima, and/or, if a trigger condition is fulfilled, the fulfilment of which depends on the height of the main maximum and/or of at least one secondary maximum of the cross-correlation. The determination of the measured quantity is modified compared with a normal operating mode and/or a message is output.

Abstract: An ultrasound flow measurement device has a vessel through which a fluid to be measured flows. An ultrasound measurement configuration with an ultrasound transducer is provided for measuring a propagation time of an ultrasound signal containing a plurality of periods along a measurement section that runs partly in a direction of flow. A controller determines a fluid flow on a basis of a propagation time measurement. The controller contains a memory, a first evaluator for determining a period duration of at least one of the periods of an ultrasound signal received after passing through the measurement section, a second evaluator for determining a spread value of a predetermined number of last received ultrasound signals, a comparator for comparing the spread value with a threshold value, and an actioning device for initiating a control action, assigned to the threshold value that has been exceeded, for the ultrasound flow measurement device.

Abstract: A method for evaluating discrete measurement data sequences of an ultrasonic flow measuring device having a recording frequency and ultrasound signal, includes determining time position or height of a maximum of a sinusoidal profile of a time sequence of evaluation values, determined as part of a measurement data sequence or cross-correlation of two sequences recorded at different positions of the device by determining a maximum evaluation value of the time sequence and evaluation values thereof adjacent thereto. Initial values, including an initial maximum value and time, are determined by quadratic fit of evaluation values. Output values including output time describing the position or output height describing the height of the maximum are determined by a determination relationship setting output values in relation with initial values and a calculation quantity formed from selected evaluation values for known recording frequency and known signal frequency and based on a known sinusoidal profile.

Abstract: An ultrasound flow measurement device has a vessel through which a fluid to be measured flows. An ultrasound measurement configuration with an ultrasound transducer is provided for measuring a propagation time of an ultrasound signal containing a plurality of periods along a measurement section that runs partly in a direction of flow. A controller determines a fluid flow on a basis of a propagation time measurement. The controller contains a memory, a first evaluator for determining a period duration of at least one of the periods of an ultrasound signal received after passing through the measurement section, a second evaluator for determining a spread value of a predetermined number of last received ultrasound signals, a comparator for comparing the spread value with a threshold value, and an actioning device for initiating a control action, assigned to the threshold value that has been exceeded, for the ultrasound flow measurement device.

Abstract: A method operates a measuring device used to determine a fluid variable. The measuring devices contains a vibration transducer driven to excite a wave in the fluid due to a test excitation signal. The wave is guided along a propagation path back to the vibration transducer or to an additional vibration transducer, thereby exciting the (additional) vibration transducer to vibrate. An output signal relating to this vibration is acquired, and a frequency of that segment of the output signal that lies in an analysis interval is determined. The analysis interval starts once the driving of the vibration transducer to excite the wave has finished, and/or once a maximum of the amplitude of the vibration is reached. The determination of the fluid variable is performed based on the determined frequency. An error message or a notification is output to a user and/or to a device external to the measuring device.

Abstract: A method for evaluating discrete measurement data sequences of an ultrasonic flow measuring device having a recording frequency and ultrasound signal, includes determining time position or height of a maximum of a sinusoidal profile of a time sequence of evaluation values, determined as part of a measurement data sequence or cross-correlation of two sequences recorded at different positions of the device by determining a maximum evaluation value of the time sequence and evaluation values thereof adjacent thereto. Initial values, including an initial maximum value and time, are determined by quadratic fit of evaluation values. Output values including output time describing the position or output height describing the height of the maximum are determined by a determination relationship setting output values in relation with initial values and a calculation quantity formed from selected evaluation values for known recording frequency and known signal frequency and based on a known sinusoidal profile.