In this work we present a new ultrasonic technique for thickness measurements in highly scattering composite materials. When two different transducers, one transmitter and one receiver, are used, because of the small radiating surface in relation to the wavelength, a strong acoustical coupling through a generated surface wave (SAW) masks the bulk wave carrying the thickness information. The time-of-arrival of the bulk wave, which appears as a singularity in the received signal, can be discriminated by performing higher order derivatives of this signal, obtaining situations in which an evident discontinuity appears in correspondence of the interference instant. We apply this technique in concrete, in order to verify its validity and to understand its application limits.
Thickness measurements based on a new time discrimination technique
Fiorillo A. S.;
1993-01-01
Abstract
In this work we present a new ultrasonic technique for thickness measurements in highly scattering composite materials. When two different transducers, one transmitter and one receiver, are used, because of the small radiating surface in relation to the wavelength, a strong acoustical coupling through a generated surface wave (SAW) masks the bulk wave carrying the thickness information. The time-of-arrival of the bulk wave, which appears as a singularity in the received signal, can be discriminated by performing higher order derivatives of this signal, obtaining situations in which an evident discontinuity appears in correspondence of the interference instant. We apply this technique in concrete, in order to verify its validity and to understand its application limits.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
