Visual Inspection

Visual inspection (VT) is a non-destructive testing method that allows the detection of discontinuities that affect the visually accessible surface of objects. It is the non-destructive method par excellence, its scope of application being extremely extensive: Identifying materials with respect to their specification and chemical composition, detection of imperfections and defects produced during a production process. Visual inspection is not only important as a test method in itself, but it is essential as a preliminary and preliminary test in the execution of any other, since it must always be carried out, even when the execution of other types of tests is planned, either. executed reduces the need to apply other subsequent tests.

In order to effectively carry out the visual test, it is as important to know how to perform the observation technically as it is to know how to interpret the observed results. Knowledge of materials, manufacturing processes and uses of the components tested are essential. Depending on the instruments used to aid vision, and the distance (or access) between the inspector and the object of study, Visual Inspection can be divided into two groups:

DIRECT VISUAL INSPECTION. The inspection is done at a short distance from the object, making the most of the inspector’s natural visual ability. Magnifying lenses, microscopes, lamps or flashlights are used, and measuring instruments such as calipers, micrometers, rulers and gauges are often used.

REMOTE VISUAL INSPECTION. Remote visual inspection is used in those cases where there is no direct access to the components to be inspected, or in those components in which, due to their design, it is very difficult to access their internal cavities. For remote visual inspection, the use of instruments such as rigid endoscopes (baroscopes), flexible endoscopes, videoscopes and fiberscopes is required, with which most internal cavities and places inaccessible to the inspector can be reached.