This course is designated for Professional Development of Welding Educators teaching secondary and post-secondary welding programs. “Non-Destructive Testing (NDT)" is testing and evaluation that does not destroy the test object. NDT is vital for constructing and maintaining all types of components and structures. Non-Destructive tests are done to detect internal or external imperfections, to determine structure, composition, or properties, or to measure geometric characteristics without affecting the form, fit, or function of the test object or material. To detect different defects such as cracking and corrosion, there are different methods of testing available, such as X-ray (where cracks show up on the film) and ultrasound )where cracks show up as an echo blip on the screen.