LABORATORIUM

Visual testing is a basic form of quality control of welded joints. They are based on the observation of the tested surface with the unaided eye, using optical instruments and devices for remote observation, their purpose is to detect material discontinuities on accessible and inaccessible surfaces, for example cracks and corrosion pitting, in the case of welded joints - fusion, concavity, lack of fusion and others This method is used at various stages of construction of operational objects, production of steel structures, pipelines: preparation of elements for welding, inspection of the joint during welding and the finished joint.

In order to properly perform VT visual testing, several conditions must be met. The first of them is appropriate lighting of the object, which must be not less than 500 lx. Equally important is the distance and position of the examinee from the surface. The distance must be less than 60 cm and the viewing angle should exceed 3 degrees. In the case of weld testing, in addition to the inspection site itself, the area immediately adjacent to the weld must also be analysed. If there is no direct access to the inspection site, inspection mirrors or other optical devices, for example, can be used for testing.

Visual testing is most often performed in conjunction with other non-destructive testing methods.