Welds and metal components
Targeted internal inspections of joints and components, mainly in the industrial field.
Technical guide · Specialist method
Structural and industrial radiography
A specialist inspection to visualize internal details and discontinuities that are not directly accessible.
Predominant in industrial inspections, radiography can also be chosen for targeted investigations on concrete and timber, if operating conditions allow it.
What is radiography?
An X-ray or gamma-ray source emits ionizing radiation that passes through the component. Materials, thicknesses and discontinuities attenuate the beam to different degrees: the recorded signal forms a radiographic image, even a digital one, to be interpreted in the context of the inspection.
It is not a complete view of the object: the quality of the information depends on the material, the geometry and the test conditions.
Where it is used
Most applications concern industrial inspection. On civil structures, its use is specific and localized.
Shipbuilding sector
Radiographic checks on elements and joints where geometry and access allow it.
Metalwork and industrial components
Localized investigations on metal elements for information not visible from the outside.
Reinforced concrete
Localized in-depth assessments on structural elements in specific cases, not routine investigations.
Timber structures
Localized internal observation of timber elements, if the test conditions are adequate.
Special internal inspections
When the diagnostic question requires details that other methods cannot provide.
What it allows to observe
Depending on the component and the investigation configuration, the image may help highlight discontinuities, voids, inclusions, honeycombing, internal configurations and specific details.
Detectability is not guaranteed: interpretation depends on image quality, material, geometry and the information available on the element.
Why it is a specialist technique
The accessibility of the element, its geometry and the organization of the campaign must be assessed before choosing the method. The use of ionizing radiation requires control of the area, qualified personnel and radiological safety management in accordance with the applicable requirements.
Radiography and other methodologies
Radiography is not part of a standard combination with GPR and tomography in routine concrete diagnostics. It can be selected when a specific diagnostic question requires a localized high-detail investigation and operating conditions allow it.
Structural GPR and ultrasonic tomography are related methodologies, with different principles and information: the choice does not imply their joint use.
Tronto IV Viaduct
In the case of the Tronto IV Viaduct on the SS 4 “Salaria”, Novatest Engineering carried out a campaign of 478 radiographic acquisitions.
The documented objective was to observe voids, internal honeycombing and the state of conservation of the reinforcing bars, with particular attention to the prestressing strands. The data describes the purpose of the investigations, not additional undocumented results.
Technical references
UNI EN ISO 9712:2022. In the industrial sector it includes radiography among the NDT methods for which it establishes requirements for personnel qualification and certification. It is not the only relevant standard for carrying out the tests.
UNI EN ISO 17636-1:2022 and UNI EN ISO 17636-2:2023. The family concerns radiographic practice for welded joints; part 2 deals with digital radiography. Applicability must be assessed against the component and the context.
Frequently asked questions
- When is radiography used?
- When it is necessary to investigate a specific portion of a component and access conditions, geometry and safety allow the inspection. Its main field of application is industrial.
- Is radiography a NDT technique?
- Yes. It is a non-destructive testing method based on ionizing radiation; in the industrial sector, UNI EN ISO 9712:2022 includes the radiographic method among those for which it defines the requirements for personnel qualification and certification.
- Can radiography be used on concrete?
- Yes, in specific cases on reinforced concrete elements, for localized high-detail investigations. It is not a routine methodology of concrete diagnostics: applicability depends on geometry, access and operating conditions.
- What are the main differences compared with GPR and tomography?
- GPR and ultrasonic tomography analyze electromagnetic and elastic responses respectively. Radiography forms an image from the attenuation of radiation through the component: it can answer specific local questions and should not automatically be added to the other methods.
- What operating conditions must be considered?
- Accessibility, the geometry of the element, the possibility of organizing the campaign and control of the area must be assessed in compliance with the applicable radiological safety requirements.
Do you need to inspect an element that is not directly accessible?
Describe the element and the information you are looking for: we will assess whether a radiographic inspection is appropriate and feasible.
Talk to a technician