Separation und Bewertung verschiedener Moden der Schallausbreitung im akustischen Wellenleiter

In this contribution it is shown that the modal components of the received signal at the end of an acoustic waveguide can be suppressed or intensified if the two electrodes of a piezo-electric ceramic are shaped in a special way. With this it is possible to measure different signals which can be used to differ between the liquids dissipation and the signal attenuation caused by the waveguide geometry as well as impedance conditions. With the help of the principal component analysis it should be possible to infer the modal amplitudes from the received signals of one ultrasonic transducer and to calculate the acoustic impedance of the liquid that is included in the wave guide.