Method for operating ultrasonic flow meter for determining volume flow rate and mass flow rate in pipeline in process-and automation engineering, involves superimposing and acoustically rectifying two acoustic signals

摘要

The method involves exciting two ultrasonic transducer elements in such a manner that the two acoustic signals are transmitted with two oscillating frequencies, respectively. The signals are superimposed and acoustically rectified, where the two oscillating frequencies have a difference of 1 Hertz or a difference of maximum 80 percent of increased oscillation frequency. The superimposition of the acoustic signals is carried out by a low-pass filter, where limiting frequency of the filter ranges up to maximum 500 percent of difference between the oscillating frequencies. An independent claim is also included for an ultrasonic flow meter comprising an ultrasonic transducer element.