Which type of radiographic film should I select?
In this article:
- Radiographic Film Selection Follows EN and ASTM Standards: The article explains how industrial radiographic film types are chosen based on EN and ASTM classification systems, ensuring compliance with global inspection standards
- Film Class Depends on Application Type: For weld inspections requiring high sensitivity, films of class C2 or C3 are recommended; for castings or general radiography, class C4 or C5 films are typically used
- High-Resolution Needs Call for Finer Film Classes: Small component inspections or magnified image evaluations benefit from class C2 or even single-emulsion class C1 films for enhanced detail
- Megavoltage Radiography Uses Higher Class Films: In high-energy applications, such as inspecting thick-walled components, class C3 films are preferred due to their ability to maintain high image contrast
- Film Type Impacts Gradient and Image Quality: Selecting the correct film class ensures optimal film gradient, contrast, and defect visibility, which are critical for accurate non-destructive testing (NDT) results
Which type of radiographic film should I select?
Most procedures and codes of good practice for the performance of industrial radiography base the choice of type of film for a specific application on the EN or ASTM classification systems. For weld inspection, when one is attempting to detect small cracks, a film of class C2 or C3 would be specified. For the examination of castings or general radiography a film of class C4 or C5 would normally be used. For small component inspection, where the image might be viewed under magnification to reveal small details, a film of class C2 or possibly even a single emulsion film of class C1 would be desirable.
In megavoltage radiography, because most equipment have a very high radiation output, class C3 films can be used for objects of great wall thickness. This has the advantage that a high film gradient can be achieved.