Overview
1. Radiographic testing (RT) uses ionizing electromagnetic radiation, either from a gamma or X-ray source,
to test a variety of metallic and nonmetallic products, such as welds, forgings, castings, fabrications, and
critical assemblies.
2. Through the use of penetration and absorption, radiography is capable of revealing discontinuities that
are internal to the product and not detectable by surface test methods.
3. Radiographic testing (RT) personnel set up, expose, process the film or digitally process the signals, and
interpret the images in accordance with written procedures, codes, and/or specifications.
Advantages of Radiographic Testing
Some of the advantages of radiography are that it:
1. is compatible with most materials.
2. provides a permanent visual record of the test object on either film or digital media.
3. reveals discontinuities within a material.
4. allows inspection of the internal structure of a component.
5. discloses fabrication errors and indicates the need for corrective action.
6. reveals assembly errors.
Limitations of Radiographic Testing
Radiography’s limitations include the following physical and economic considerations:
1. Radiography requires accessibility to both sides of the test object.
2. Small discontinuities that are not parallel with the radiation beam are difficult to image or detect.
3. Radiography is an expensive testing method.
4. Film radiography is a time-consuming testing method. After taking the radiograph, the film must be
processed, dried, and interpreted.
5. Depth of a discontinuity may be difficult to determine.
1
Introduction to Radiographic Testing
Lesson 1
1. Radiographic testing (RT) uses ionizing electromagnetic radiation, either from a gamma or X-ray source,
to test a variety of metallic and nonmetallic products, such as welds, forgings, castings, fabrications, and
critical assemblies.
2. Through the use of penetration and absorption, radiography is capable of revealing discontinuities that
are internal to the product and not detectable by surface test methods.
3. Radiographic testing (RT) personnel set up, expose, process the film or digitally process the signals, and
interpret the images in accordance with written procedures, codes, and/or specifications.
Advantages of Radiographic Testing
Some of the advantages of radiography are that it:
1. is compatible with most materials.
2. provides a permanent visual record of the test object on either film or digital media.
3. reveals discontinuities within a material.
4. allows inspection of the internal structure of a component.
5. discloses fabrication errors and indicates the need for corrective action.
6. reveals assembly errors.
Limitations of Radiographic Testing
Radiography’s limitations include the following physical and economic considerations:
1. Radiography requires accessibility to both sides of the test object.
2. Small discontinuities that are not parallel with the radiation beam are difficult to image or detect.
3. Radiography is an expensive testing method.
4. Film radiography is a time-consuming testing method. After taking the radiograph, the film must be
processed, dried, and interpreted.
5. Depth of a discontinuity may be difficult to determine.
1
Introduction to Radiographic Testing
Lesson 1