Wallace, G.; Hutchinson, E.F. 1994 Gammascan Institute of Geological & Nuclear Sciences science report 94/22 11 p.
Abstract: A description is given of an instrument designed to provide digital radiographs of engineering-type structures or components. Either X-rays or gamma rays can be used and the techniques is both on-line and non-invasive. Although the use of radioisotopic sources makes full imaging relatively slow, the digital format and provisions included for operator interaction can be combined to increase efficiency significantly. In addition to the normal shadow radiographs, the instrument is capable of locating the depth at which features are buried within, for instance, a wall. Laboratory tests and examples are described. The parameters governing the application of the techniques for field use are discussed, and comparisons made with present techniques. (auth)