Radiography

Article By:

Tenney, Gerold H. American Society for Nondestructive Testing, Inc., Los Alamos, New Mexico.

Clark, George L. Formerly, Department of Chemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois.

Berger, Harold Industrial Quality, Inc., Gaithersburg, Maryland.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.569700

The technique of producing a photographic image of an opaque specimen by the penetration of radiation such as gamma rays, x-rays, neutrons, or charged particles. When a beam of radiation is transmitted through any heterogeneous object, it is differentially absorbed, depending upon the varying thickness, density, and chemical composition of this object. The image registered by the emergent rays on a photographic film adjacent to the specimen under examination constitutes a shadowgraph or radiograph of its interior. Radiography is the general term applied to this nondestructive film technique of testing the gross internal structure of any object, whether it be of the chest of a patient for evidence of tuberculosis, silicosis, heart pathology, or embedded foreign objects; of bones in case of fractures or of arthritis or other bone diseases; or of a weld in a pipe to observe cracks, inclusions, or voids. Radiography with x-rays is commonly used in both medical and industrial applications. Industrial work also involves gamma and neutron radiography. Radiography with charged particles is under development. Most of this discussion will be concerned with radiography with x-rays and gamma rays. See also: Charged particle interactions; Gamma rays; Neutron; X-rays

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