An acoustic wave is usually produced by a piezoelectric transducer. Intense, small electrical pulses from the ultrasonic machine cause the transducer to be tuned to the desired frequency. The acoustic wave is focused by the lens located in front of the transducer and produces a spherical acoustic wave from the surface of the sensor. The wave travels to the body and focuses on a desirable depth.The return of the acoustic wave to the inverter has the same effect as the sending of the acoustic wave but from the reverse. That is, the returned acoustic wave causes the transducer to vibrate at its frequency and then convert that vibration into electrical pulses, which are processed and transformed into images.SAM uses a focused audio signal to research, measure, or visualize an object, a process known as Scanning Acoustic Tomography. Used in error analysis and non-destructive evaluations. It has a wide range of applications, including biological and medical research. Also the semiconductor industry uses it to detect gaps, faults and failures in integrated circuits.The lens system is the most important tool of a SAM. As mentioned, a high frequency acoustic signal is produced in the lens system by a transducer. The signal is propagated through a medium having a high acoustic resistance and then focuses, with the help of a lens, on the other end of the medium. This is immersed in liquid to fill the gap between the lenses and the object under consideration. Immersion in the liquid provides a kind of “acoustic continuity” as it achieves a smooth transition between the medium and the object to be examined. The focused beam, interacting with the object, is partially reflected and diffused by the object and partly propagated through the object. If the reflected wave is detected, the microscope operates by reflection. When the transmitted acoustic wave is recorded by a second lens, then the microscope operates with propagation (figure 3) (Khuri-Yakub, 1993).An acoustic wave is usually produced by a piezoelectric transducer. Intense, small electrical pulses from the ultrasonic machine cause the transducer to be tuned to the desired frequency. The acoustic wave is focused by the lens located in front of the transducer and produces a spherical acoustic wave from the surface of the sensor. The wave travels to the body and focuses on a desirable depth.The return of the acoustic wave to the inverter has the same effect as the sending of the acoustic wave but from the reverse. That is, the returned acoustic wave causes the transducer to vibrate at its frequency and then convert that vibration into electrical pulses, which are processed and transformed into images.The greater the difference between the acoustic resistances, the greater the reflection. If the pulse “collides” with gas or solid, then the difference in density or rather better in the Young modulus is so great that most of the sound energy is reflected and it becomes impossible to penetrate the wave deeper. For this reason a special dispersion medium (water, gel) is also used to make a smooth change of Young modulus.

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