What is the term for moving a search unit over a test surface, either manually or automatically?

The term for moving a search unit over a test surface, either manually or automatically, is known as scanning. This process is essential in nondestructive testing (NDT) as it allows for the systematic collection of data regarding the material being tested. During scanning, the search unit (like an ultrasonic transducer) generates waves that interact with the material, enabling the detection of defects or irregularities.

Scanning is a fundamental concept in various NDT methodologies, as it helps ensure comprehensive coverage of the test area. The technique can vary in speed, pattern, and distance between scans, depending on the testing requirements and the characteristics of the material being inspected. In contrast, testing is a broader term that can refer to various procedures for evaluating materials, and 'sweeping' often refers to a specific type of motion rather than the overall process. Assessment involves evaluating the results of tests but does not refer to the physical action of moving over the test surface.