Which parameter is most significant for clarity in the far field of Ultrasonic Testing?

In Ultrasonic Testing (UT), clarity in the far field is heavily influenced by beam divergence. Beam divergence refers to the spreading of the ultrasonic waves as they propagate through the medium. In the far field, this divergence leads to a reduction in the intensity of the sound waves, which can impact the ability to distinguish echoes from flaws or interfaces.

As sound waves spread out, the energy becomes more dispersed, making it more challenging to achieve a strong echo from a specific target. Reduced beam divergence can help maintain a concentrated area of sound intensity, allowing for clearer and more distinct echoes, which are essential for accurately identifying and characterizing discontinuities or flaws in the material being tested.

Other factors such as total sound wave intensity, angle of incidence, and echo time delay do contribute to ultrasonic testing but are not as crucial for achieving clarity in the far field. For instance, while total sound wave intensity can affect the overall effectiveness of the test, it does not directly influence how well echoes can be differentiated in the far field as beam divergence does. Similarly, the angle of incidence is important primarily for directivity and reflection efficiency rather than clarity at distance, and echo time delay concerns the timing of received signals more than their clarity.