This unit of instruction deals with the study of X-ray and Gamma Ray Radiographic Testing and infra-red thermal testing of specimens without destruction. Theory and principles are covered in detail. Many known samples are used as standards and considerable laboratory and field use of this equipment is involved. Motion picture films and color slides are listed to be used with the lesson. Goals, specific block objectives, and a bibliography are listed in the booklet. A posttest sample, with answers, is included. (EB)