Tomography overview
The use and implementation of computer aided tomographic techniques in the late 1970’s allowed users to access an innovative technology for significant contributions for medical applications. Soon after, tomographic techniques were utilized for industrial applications, enabling users to identify and locate internal failures, without cutting open the industrial part. Computer aided tomographic techniques, such as Industrial Computed Tomography (CT), have revolutionized the way industry leaders qualify and validate industrial parts.
What is tomography?
Tomography is a process of developing a three dimensional image of the internal features of a solid object. The term tomography originates from the Greek term “Tomos”, meaning section or slice. According to the Merriam-Webster dictionary, tomography is a method of producing a 3D image of the internal structures of a solid object by the observation and recording of the differences in the effect on the passage of waves of energy impinging on those structures.
Commonly, tomography is used in combination with x-ray technology, in order to manipulate and reconstruct 2D x-rays into tomographic images which are used to develop a 3D model for the external and internal part surface and structures.
How does tomography work?
Tomography refers to the process of capturing images by sections, through some wave of energy; most commonly an x-ray source. For x-ray computed tomography, an x-ray source must be positioned on the opposite side of the detector panel. The radiation is exposed onto the subject being scanned, which is placed between the x-ray source and detector panel. The radiation passes through toward the detector panel and 2D cross sectional slices are captured in pre-determined increments. These tomographic images are then reconstructed using a software, into a 3D model.
Types of tomography
Although computed tomography is one of the most common type of industrial tomography, there are many other types. Some of the most significant types of tomography include:
- X-ray – Computed Tomography
- Gamma rays – SPECT
- Radio-frequency – MRI
- Electron-positron annihilation – PET
When is X-ray tomography necessary?
For a 3D model to exist, sectional slices of 2D x-ray images must be captured and reconstructed. Thus, the process of capturing cross sectional slices, or tomographic images is very necessary in order to develop a 3D model. Furthermore, if a user wants to access the internal structures of an object, tomographic images must be captured and analyzed independently, or reconstructed into a 3D model for extensive analysis.
Uses and applications of 3D tomography
Tomographic images assist in developing a 3D rendering or 3D model for inspection purposes. There are many uses of this process including, but not limited to:
- Quality control management tool
- Failure investigation purposes
- Internal part analysis
- Qualify part in its entirety
- Accurate measurement tool
- Dimensional analysis
- Repeatability test
Benefits of tomography
Tomography assists users in accessing certain areas of an object internally, without having to cut it open. This allows users for limitless opportunities and countless benefits, some of which include:
- Internal part access to locate failures
- Internal access for dimensional analysis
- Nondestructive testing
- Save on cost of manufacturing (NDT) and reduce time to production
- Wall thickness distribution analysis
- Comparison analysis
