Standard Specification for Illuminators Used for Viewing Industrial Radiographs
This specification provides the recommended minimum requirements for industrial radiographic illuminators used for viewing industrial radiographic films using transmitted light sources. The function of the illuminator is to provide sufficient illumination and viewing capabilities for the purpose of identification and interpretation of radiographic images. The luminance of the transmitted light shall not be less than 30 candelas per square metre for film densities equal to or less than 2.5 optical density and not less than 10 candelas per square meter for film densities greater than 2.5 optical density. If the illuminator has a diffusing screen, the light shall be sufficiently divergent so that both eyes of the observer receive rays from all parts of the screen. The maximum illuminator luminance, and divergence and diffusion of light shall be tested to meet the requirements prescribed.
