Inspection of high voltage cables using X-ray techniques

Defects that are accidentally introduced into high voltage cable joints during manufacture significantly decrease the working lifetime of the cable system. As a measure of quality assurance the joint can be non-destructively tested using X-rays to image the structure of the joint. The image produced can then be inspected for defects such as the thinning of the semiconducting sheaths or the insulation thickness. The location of the boundaries of these insulation components can be found by differentiating the profile of the X-ray image surface. Once these locations are known it is possible to calculate the thickness of these components. These thicknesses can then be used as a measure of quality assurance for the cable joint.