We speak of a discontinuity as the interruption of the typical (or expected) structure of a welded joint. In this sense, it can be considered as the lack of discontinuities
homogeneity of physical matter, mechanical or metallurgical weld. The existence of discontinuities in a welded joint does not necessarily mean that it is defective. this condition depends on the use to be given to the board, and the discontinuity is characterized by the measurement and comparison of the observed properties against established acceptance levels.