What depicts a difference between a raster scan using a phased array unit and a conventional system?

The correct choice illustrates a significant advantage of phased array technology in performing raster scans. In a raster scan using a phased array unit, a single probe is capable of dynamically adjusting both its angle and focal range during the scanning process. This ability allows for the efficient gathering of data from multiple perspectives without the need to physically reposition the probe for each angle.

This versatility means that a single probe can effectively cover a variety of scanning parameters, making it possible to detect and assess different types of flaws or indications with a single pass. As a result, this capability enhances the efficiency and effectiveness of inspections, allowing for detailed evaluations that wouldn’t be possible with a conventional system, where multiple probe configurations may be necessary to achieve similar results.

The other options do not accurately reflect the differences. For instance, while couplant is an important consideration for ultrasonic testing, the statement regarding its requirement in raster scans does not directly address the technological capabilities of phased arrays versus conventional systems. Similarly, while raster scans may have a user-friendly interface, implying simplicity does not speak to the unique functionality offered by phased array technology. Lastly, while raster scans can indeed be applied across various industries, this broad applicability does not inherently reflect a difference in capability or operation between phased array and conventional scanning