What are relative exposure factors?
What are relative exposure factors?
“Relative exposure factors” can be used to convert an exposure chart for one type of film to another film, although still for the same radiation energy. These factors are not constant for different radiation energies and should, therefore, be used with some caution. Some examples of relative exposure factors for Agfa Structurix films are shown in table 1-9.
These are the factors by which to increase or decrease the exposure-time when using the types of film other than those for which the exposure charts have been prepared.
In view of the widely-varying quality of the radiation emitted by different types of X-ray equipment and the appreciably different characteristics of the various types of X-ray films made for industrial use, caution should be exercised in applying these relative exposure factors generally.
Darkroom technique too, plays an important role and a uniform manual or automatic development process is, therefore, essential.
With radioactive sources, which give a constant quality (hardness/energy) of radiation, the relative exposure factors listed can be used quite safely.