The third edition of the Level II Study Guide: Radiographic Testing (RT) builds on the work of the previous editions. The guide includes fundamental information intended to assist the candidates preparing for Level II radiographic testing examinations such as the ASNT Central Certification Program. Included are sample questions with references for further study and a glossary of key terms. New topics covered in this update include ionization of matter, scatter radiation, image sharpness, film handling and storage, and replenishment of darkroom chemicals, among others. This study guide provides the basic information to prepare a candidate for Level II examinations in radiographic testing.