MEASURING PHYSICAL DENSITY WITH X-RAY COMPUTED-TOMOGRAPHY

X-ray computed tomography (CT) can quantify variations in material den sity. However, little practical information concerning accurate transl ation of CT numbers (an approximation of the material's linear attenua tion coefficient) into mass density exists. We describe our developmen t of this methodology. Issues addressed include the physics of mapping CT density to mass density; development and scanning of density stand ards; post-reconstruction filtering to reduce the effects of quantum n oise; and segmentation of the object data from the surrounding medium, Examples of our use of this procedure in studying density gradients d uring powder pressing and firing are given. (C) 1997 Elsevier Science Ltd. All rights reserved.