| abstract |
A two step method of scanning objects to gain information about material content comprises the steps of providing a radiation source and a radiation detector system spaced therefrom to define a scanning zone therebetween. In a first scanning step, an object is moved relative to the source and detector system, intensity information about radiation incident at the detector system after interaction with the object as it passes through the scanning zone is collected, variation of intensity as the object moves through the scanning zone is used to identify anomalous structures and / or absence of homogeneity in the object.In a second, subsequent scanning step an object is located in fixed position in the scanning zone and collecting intensity information collected, analysed against a suitable functional relationship relating transmitted to incident intensity, and the results compared with a library of suitable data to provide an indication of material content. |