Selecting a Nondestructive Testing Method, Part IV: Radiography

After visual and optical testing (VT), the next method of nondestructive testing (NDT) most commonly employed in industry is radiographic testing. Also simply referred to as radiography, it is perhaps the most versatile of the nondestructive testing methods.[1] The basic radiographic process in use today is in large part still the same as it was when it was introduced in the late 1800s. Radiography uses radiation energy to penetrate solid objects in order to assess variations in thickness or density. The second part of the process involves capturing a shadow image of the component being inspected on film using procedures similar to those that technicians used when the technology was first developed. Identifying density differences on an X-ray, which indicate flaws or cracks, is still the foundation of radiographic analysis.