Visual inspections also commonly called as Visual examination or Visual Testing VT on objects, parts, components engineering structures is the oldest and reliable non-destructive testing method. This test method is applied to almost every product as a quality assurance tool. Generally, the most detrimental unacceptable discontinuities in the objects or items are the surface opening discontinuities. Visual scanning, inspection or testing can successfully detect these unacceptable surface discontinuities without applying expensive test methods.
There are several aids to facilitate and enhance visual inspection. One of the best example is Boroscopy. Boroscopy is applied whenever there is a restriction or access limitations to examine the area of interest with naked eyes. Some of the examples of restricted access are welded pipes, in-service piping, pressure vessel, engine parts, or similar closed assemblies.