Visible dye light absorption properties of processed radiographic film

The visible absorption spectra of Kodak X-Omat V film, which had been expos ed to various doses of radiation, have been investigated to analyse the dos imetry characteristics of the film with various densitometers. Common densi tometers can use fluorescent light (broad band visible), helium-neon (632 n m) or other spectra of specific bandwidth. The visible absorption spectra s how a slight peak in absorption at approximately 580 nm and another at 630 nm caused by the base material of the film. The optical density of the film is shown to increase almost equally at all wavelengths within the visible region with increases in applied dose. By evaluating the results for the br oad band spectra and specific wavelength optical density it is shown that a relatively uniform response is expected for all densitometers that work wi thin the visible region as well as in selected infrared wavelengths. Thus s imilar optical density to dose response curves for X-Omat V radiographic fi lm should be produced for all types of densitometers. no matter what type o f light source is used for illumination. Thus it is most efficient to have a densitometer with a light source suitable for radiochromic film, which ca n also be used with radiographic film.