Patent ID: 8233588

Claim:
A method of obtaining radiation transmission data from an object comprising the steps of: providing a radiation source and a radiation detector system spaced therefrom to define a scanning zone therebetween, the detector system being capable of detecting and collecting spectroscopically resolvable information about incident radiation; collecting one or more datasets of transmitted intensity information about radiation incident at the detector system and hence interaction of an object in the scanning zone with incident radiation at at least one scanning position from radiation received at the detector system after transmission through the object; resolving each said intensity dataset across at least three frequency bands within the spectrum of the source to produce an intensity data item for each band; evaluating a numerical relationship between the intensity data items for at least two pairs of such frequency bands in a given intensity dataset to obtain a numerical indicator in functional relationship with a characteristic physical material property associated with the transmission of a source radiation that varies functionally with the radiation energy; comparing the numerical indicator with a library of data indicative of such characteristic physical material property for a range of potential component materials, in order to obtain an indication of the likely composition of any object producing such intensity dataset.