Observations of Density Variations in Tobacco Rods by Neutron Radiography

Neutron radiography was used to study the density of tobacco rods. Density variations in individual rods caused by local packing variations and the presence of more dense materials in the blend were easily discernible in both static and real-time radiographs. A density resolution of 0.35 mm was observed in the real-time system. By averaging center line density scans for several rods with the aid of an image processor, large scale variations in the density such as the increased packing at the rod ends could be measured. Comparison of the results from neutron radiography with those obtained by cutting rods into sections and weighing the sections showed good agreement. Both methods indicated the lighting end was approximately 9 % more dense than the middle of the rod. This work has demonstrated that neutron radiography can be used to provide accurate density information about cigarette rods with considerably greater resolution and in much less time than sectioning and the commercial beta ray gauging technique.