What does a B-scan represent in Ultrasonic Testing?

A B-scan in Ultrasonic Testing (UT) represents a two-dimensional cross-sectional image derived from A-scan data. In ultrasonic testing, an A-scan provides a single line of reflection data showing signal strength against time, typically portraying the distance to the reflecting surface. In contrast, the B-scan takes this information and organizes it into a two-dimensional view, displaying multiple A-scan readings across a certain area or depth.

This visualization is useful for identifying and analyzing features within materials, such as flaws or varying thicknesses. The B-scan can show the depth of the material and the location of any detected anomalies in a more accessible format, allowing for easier interpretation and assessment of the inspected component.

In comparison, the other options do not accurately characterize a B-scan. A line graph of signal reflections would describe an A-scan, while a representation of wave frequencies does not convey the structural information perceived through a B-scan. Similarly, a digital output of noise levels relates to signal quality and would not provide the detailed cross-sectional imagery associated with B-scans.