Fig. 5. Scaled surface area of the particles as a function of voxel size analyzed with simulated media. (A) The calculated surface area, divided by the analytically determined surface of the spheres, converges to the true value (1.0) with decreasing voxel size. The large symbols indicate the voxel size of the measurements with X-rays from tubes (black) or thermal neutrons (gray), respectively. (B) The absolute value of the change of area with decreasing voxel size is constant or decreases for voxel sizes smaller than 10 to 15% of the mean particle radius (arrows). The resolutions of the tomography did not fulfill this condition.