NDT uses special equipment and methods to learn (variations in structure, minute changes in surface finish, and the presence of cracks or other physical discontinuities, to measure the thickness of materials and coatings and to determine other characteristics about the object) without harming the object.
NDT is a science. It uses physics, chemistry and mathematics. NDT methods are based on a particular scientific principle, & use some form of energy to collect information
NDT is an art. Choosing the right method and technique is an important part of performing NDT to maximize the “Probability of Detection”
No single NDT method will work for all flaw detection or measurement applications. Each of the methods has advantages and limitations when compared to other methods