Radiography is one of the several methods of Non-Destructive Testing (NDT) offered by the skilled technicians at Encorus. There are two different methods of conducting a radiography test: computed radiography and traditional radiography. Computed radiography is the more modern of the two processes, and has several advantages over traditional radiography. To understand how computed radiography is better than traditional radiography, it is important to know how radiography works.
Radiographic testing (RT), commonly known as radiography, is a method of non-destructive examination which uses either x-rays or gamma rays to see inside the component or specimen, creating a hard copy image of the item. RT is used to inspect welds, machined parts, pipes, vessels and tanks, concrete, plate metal, and ceramics. Much like a medical x-ray or x-ray security screening at the airport, RT can reveal irregularities or defects within the object being examined without damaging it. A trained radiographer can locate a defect as well as identify its type, size and location based on subtle variations in the film density. Both computed and traditional radiography use X-rays and gamma rays; however, there are several differences in the procedures that follow.
According to DÜRR NDT, “in computed radiography, when imaging plates are exposed to X-rays, or gamma rays, the energy of the incoming radiation is stored in a special phosphor layer. A specialized machine known as a scanner is then used to read out the latent image from the plate by stimulating it with a very finely focused laser beam. When stimulated, the plate emits blue light with intensity proportional to the amount of radiation received during the exposure. The light is then detected by a highly sensitive analog device known as a photomultiplier (PMT) and converted to a digital signal using an analog-to-digital converter (ADC). The generated digital X-ray image can then be viewed on a computer monitor and evaluated. After an image plate is read, it is erased by a high-intensity light source and can immediately be re-used. Imaging plates can typically be used 1000 times or more depending on the application”.
The main advantages of computed radiography are that the imaging plates are reusable, no darkroom or chemicals are needed, the time required for exposure and processing of the image is reduced, digital information can be easily exchanged and archived, it presents a safer working environment for operators, and it is more environmentally friendly.
The computed radiography process is faster and more efficient, and presents a more environmentally friendly work atmosphere. Overall, computed radiography is the superior option when compared to traditional radiography. It offers a safer and more effective method to determining if a piece of material should be repaired or closely monitored. If you require computed radiography services or other NDE testing, please contact Jeremy Lake at (716) 592-3980 ext. 133, or [email protected].