Which type of scan provides a two-dimensional view of all A-scans with a fixed aperture that steers through a sequence of angles?

The correct response highlights the unique characteristics of the sectorial scan, which is specifically designed to deliver a two-dimensional view of A-scans while employing a fixed aperture that systematically steers through various angles. This type of scanning is particularly effective in visualizing the internal structure of a test material by displaying the data in a planar format, which allows for an enhanced understanding of the dimensions and locations of any indications or anomalies detected during the inspection process.

In a sectorial scan, the transducer’s beam is directed across a defined sector of angles, and as it moves, it collects and displays multiple A-scans in a format that resembles a slice through the object. This approach is crucial for applications requiring a detailed examination of welds, joints, or areas that may contain flaws, as it provides insights into the depth and position of the detected features.

Other scan types, such as B-scans, linear scans, and C-scans, operate under different principles. For example, B-scans generate cross-sectional images but do not incorporate the angle-steering mechanism of the sectorial scan. Linear scans typically involve moving the transducer along a straight line without the angular steering aspect, which limits the visualization capabilities. C-scans typically provide a plan view of