Which type of phased array scan is performed with different focal depths?

The dynamic depth focusing (DDF) scan is characterized by the ability to perform ultrasonic inspections at varying focal depths. This scanning technique allows the operator to adjust the focal point of the ultrasound beam as it is sent through the material, effectively optimizing the resolution and sensitivity at multiple depths within the inspected object. This flexibility is crucial for assessing defects that might be located at different layers or surfaces within a component.

In contrast to other scanning methods, DDF enhances the imaging of features that may not be seen clearly with fixed focal depths. The ability to focus dynamically can significantly improve the detection of flaws, providing a more thorough evaluation of the material integrity. It is particularly useful in applications such as weld inspections or when examining materials with varied thicknesses.

The other scanning techniques listed do not convey the same functionality or purpose. For instance, E-scans and S-scans typically don’t offer the same level of adaptability in focusing depths, focusing either on specific angles or sectors rather than allowing for ongoing adjustments during the scan. Compound sector scans employ a method of overlaying information from multiple angles but also do not inherently allow for dynamic focusing at different depths in the same way that a DDF scan does.