Non-Destructive Testing (NDT) is an activity closely related to the quality and reliability of products, and to the reliable and safe operation of industrial plants. Physical measuring techniques are used to examine parts of constructional assemblies for hidden imperfections and defects. A wide choice of measuring techniques is available to meet the demand of examining a wide variety of materials such as metals, plastics, rocks, as well as different structures and sizes ranging from semiconductor chips to nuclear reactors and off-shore oil platforms. Activities in the field of NDT encompass: Fundamental research to understand and describe the way in which reactions of certain imperfections to a physical measuring technique can be optimized and used to assess type and grade of imperfection; Methods to characterize materials and materials properties; Applications in product quality control; Applications in plant inspection to ensure a reliable operation of components, avoiding damage to both man and environment, as well as financial losses; Personnel education and qualification schemes; The spread of NDT applications to newly industrialized countries.