Heijastusultraääni

Heijastusultraääni, also known as reflected ultrasound or simply ultrasound reflection, refers to the phenomenon where ultrasonic waves bounce off boundaries or interfaces within a material. When an ultrasound beam encounters a change in acoustic impedance, such as the boundary between two different materials or a defect within a material, a portion of the transmitted sound energy is reflected back towards the source. The amplitude and timing of these reflected waves provide valuable information about the internal structure and characteristics of the object being examined.

In practical applications, this principle is fundamental to ultrasonic testing (UT) and medical imaging. In non-destructive testing, ultrasonic transducers emit sound pulses into a material. These pulses travel through the material and are reflected by internal flaws like cracks, voids, or inclusions, as well as by the back wall of the component. By analyzing the time it takes for the reflected echoes to return and their intensity, inspectors can determine the location, size, and nature of these discontinuities.

In medical ultrasound, transducer probes emit high-frequency sound waves into the body. These waves travel through tissues and are reflected at boundaries between different tissues (e.g., muscle and bone, fluid and soft tissue) or by organs. The returning echoes are detected by the transducer and processed by a computer to create real-time images. The variations in echo strength and arrival time are converted into brightness and position on the display, allowing for visualization of internal organs, blood flow, and fetal development. The effectiveness of heijastusultraääni depends on factors such as the material properties, the frequency of the ultrasound, and the nature of the interface.