Applications of an X-Ray Sensitive Television System for Nondestructive Testing

A television X-ray image enlargement system capable of directly detecting images developed by penetrating radiations is serving as an inspection tool for nondestructive testing. This system provides instantaneous X-ray images having 30X enlargement on a television screen. A special television camera tube detects the X-ray image and transforms the X-radiations to a video signal at a 1/30 sec frame rate when using standard television imaging operation.

Original development of the television X-ray imaging system was for inspection of weldments and material reliability in aerospace vehicles. The contrast sensitivity of this system has shown 2% thickness change in 1/4 in. steel and 1 in. aluminum thicknesses. Its resolution capability has repeatedly revealed 500 μ in. detail; however, with careful attention to operational techniques, 300 μ in. detail can be visualized.

Specimen motion speeds up to approximately 18 in./minute can be used without objectionable image blurring. The system's capability to respond to dynamic conditions, coupled with remote manipulation of devices, under inspection, provides instrumentation which can reveal many hidden defects in materials and structures.