Which technique is described as "through-transmission ultrasonic testing"?

Through-transmission ultrasonic testing refers to a method where the ultrasonic beam is transmitted from one transducer through the material being inspected to another transducer located on the opposite side. This technique is effective for detecting voids, cracks, or inclusions within the material as it allows for the assessment of the complete thickness of the component. By using two transducers placed on either side of the test object, one to send the sound waves and the other to receive them, the technique enables a clear evaluation of material integrity.

The description of the technique underscores the importance of the beam passing entirely through the structure, as this allows for comprehensive monitoring of any defects that may be present within the thickness of the material. The sound waves' amplitude and time-of-flight provide critical information about the internal conditions of the structure.

The other choices do not encapsulate the essence of through-transmission testing. For instance, having multiple transducers on the same side does not align with the fundamental principle of this technique that relies on the transmission of the ultrasonic wave through the material to a receiver positioned on the opposite side. Similarly, indicating that only solid materials are used misrepresents the applicability of through-transmission methods, as they can be employed in various types of materials. Lastly, coupling