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Film Replacement by Digital Techniques in Weld Testing

Industrial segments involved with equipment testing have attempted to replace conventional film radiography with digital radiography, in which the use of phosphor imaging plates or digital detector arrays provide the advantages of working with digitized images shown on a computer screen. However, due to the insufficient resolution of these detectors and to the gaps in general knowledge and practical experience, the replacement process is carried out in a cautious manner, always after validation with conventional film. This work discusses the correspondence between image quality, detectability and fulfillment of regulatory requirements based on the practical experience of our company using the double-wall double-image technique in its research and field work. We conclude that while substitution of digital techniques is possible, the fulfillment of specific detectability and quality requirements for these techniques must be taken into account. At present, conventional radiography still provides higher quality than computed radiography, although it is surpassed by direct radiography.

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