ASTM Reference Radiographs
Available at Beuth webshop
Reference radiograph sets are collections of radiographic images showing graded levels of discontinuities which can occur in castings and weldments.
Discontinuities in castings such as sponge or dendritic shrinkage are difficult, if not impossible, to describe in words. Gas porosity in weldments or in aluminum and magnesium castings is another example of a discontinuity which does not lend itself well to description by the written word. These discontinuities can readily by evaluated by comparing them to a reference radiograph of the same discontinuity type.
For each discontinuity type there can be four to eight graded levels, with level one being the best. Some of the discontinuity types illustrated are gas holes, shrinkage, foreign material inclusions, incomplete fusion, and penetration and porosity.
ASTM reference radiograph sets are recognized throughout the world and many material specifications, both military and commercial, specify their use for the determination of product acceptability. They may be used in totus, or, specific illustrations and grade levels may be selected based on the end use of the product being evaluated.
Using reference radiographs enables the film interpreter to make fast and accurate determinations of discontinuity type and acceptability. The interpreter is given a visual image for comparison rather than a table or graph and does not need to resort to elaborate measurements of size and spacing.
Reference radiographs allow product designers, product manufacturers, and product inspectors to "speak the same language" when it comes to "what it should be," "what I have to make," and "what really is."