Radiographic testing (RT) is one of the most efficient and economic NDT methods for volumetric inspection; ensuring safe, reliable construction and ongoing use of critical infrastructure around the world. The penetrating radiation from isotope based gamma ray and accelerator based x-ray generators provide a unique mechanism for creating an image based on the differential absorption of photons in a sample. Unfortunately, the mechanisms of photon radiation interactions with matter that allow for weld quality inspection, measurement of corrosion/erosion in pipe wall, etc. create negative externalities in many environments where RT is often performed.
Conventional radiography inspection works by using a special film that reacts to the radiation passing through the equipment, creating the picture to be examined. Because the radiation is captured on film as a part of the process, conventional radiography always provides a permanent, physical record of the test results.
Digital radiography uses a phosphor screen or flat panel containing micro-electronic sensors to capture the radiation rather than a film. The resulting image is stored digitally, instead of on film. Digital radiographs tend to be easier to store and show less image degradation.
SCAR is more than a radiography device. It is a radiography concept consisting of the radiography device and source, accessories such as positioning fixtures and shielding, and proper techniques to address both the primary beam and scatter radiation to inspect the integrity of various materials and structures. This portable device utilizes gamma radiation or X-rays to create detailed images of the internal composition of pipelines, welds, and other critical components.
