Digital Detector Array Radiography – DDA RT
Digital Detector Array (DDA) Radiography – Clear Immediate Records
IRISNDT applies DDA radiography to obtain crystal clear images of the cross-sections of components (many operating and with insulation). Unlike Computed Radiography (CR), with DDA one can see an image immediately without processing through a computer. Different than traditional RT with film, an image develops without processing (and immediately). The digital image serves as a chronological record of the condition of the component; it can be stored, accessed and compared as easily as any other digital data.
IRISNDT personnel use DDA:
- To monitor pitting and overall losses of piping through profile images (shadow shots).
- To examine insulated and non-insulated piping components.
- To examine for corrosion under insulation.
- To monitor the erosion/corrosion losses of components within insulated piping.
- To allow personnel from multiple remote locations to view the data on FTP sites.
- To monitor the operating (open/close) condition of valves.
- To examine rubber components for fabrication flaws.
- To assess geophysical core samples.
- Saves time and improves productivity over conventional film applications. The exposure time is shorter than that needed for film.
- Views multiple components (valves, pipe, fittings and threaded parts) all in the same image.
- Reduces the number of shots (and radiation time) needed to assess piping conditions.
- Can adjust brightness and contrast.
- Can magnify and process images.
- Can measure dimensions and calculate remaining thickness values.
- Can improve image evaluation.
- Operates on 120volt or on battery power.
- Works with Ir-192, Co-60 and X-ray sources.
To obtain DDA radiographs, one follows a digital camera like work process. The DDA panels have scintillators that convert radiation to light; the panels further process the light to obtain digital radiographs.
Safety is a fundamental consideration when using radiation. Clearance of areas adjacent to the component from persons or items that may be affected by radiation is required. A significant radiation dose can cause physical changes in the human body. Strict Federal and Provincial regulations, coupled with highly trained and qualified personnel ensure the safety of everyone.