X-rays are used to produce images of objects using film or other detector that is sensitive to radiation. The test object is placed between the radiation source and detector. The thickness and the density of the material that X-rays must penetrate affects the amount of radiation reaching the detector. This variation in radiation produces an image on the detector that often shows internal features of the test object.

Main Uses

Used to inspect almost any material for surface and subsurface defects. X-rays can also be used to locates and measures internal features, confirm the location of hidden parts in an assembly, and to measure thickness of materials.

Main Advantages

  • Can be used to inspect virtually all materials.
  • Detects surface and subsurface defects.
  • Ability to inspect complex shapes and multi-layered structures without disassembly.
  • Minimum part preparation is required.



  • Extensive operator training and skill required.
  • Access to both sides of the structure is usually required.
  • Orientation of the radiation beam to non-volumetric defects is critical.
  • Field inspection of thick section can be time consuming.
  • Relatively expensive equipment investment is required.
  • Possible radiation hazard for personnel