A photographic image produced by passage of radiation through an object onto film. Variations in the amount or intensity of radiation are used to determine thickness or composition of material, as well as to detect flaws such as slag, porosity, crack and inclusions. Uses X-Ray radiation generated by an X-Ray tube or Gamma radiation generated from iridium, selenium or cobalt sources.


  • Permanent record of test in the form of easily interpretable radiograph.
  • Cost effective and safe.
  • Highly sensitive.
  • Versatile in examining a variety of shapes and sizes.
  • Volumetric inspection that eliminates need to disassemble component.


  • Thickness limitations based on material density and energy used.
  • Can be time consuming.
  • Radiation hazard.
  • Cracks oriented perpendicular to the x-ray beam may not be detected.
  • Electrical source required for x-ray tube inspection.