Bull. Spec. CORESTA Congress, Jerez de la Frontera, 1992, p. 100, ST26, ISSN.0525-6240
Dynamic mass measurements of cigarettes by neutron radioscopy
Philip Morris USA, Richmond, VA, USA
Neutron radioscopy is a technique that uses a beam of neutrons and a video-based neutron imaging system to produce real-time images of an object. The images, or more correctly, the two-dimensional projections of the object, look like X-ray images and the two methods are conceptually very similar. However, neutron radioscopy is particularly well suited for imaging cigarettes and other objects containing organic materials because the neutrons are attenuated by hydrogen atoms. In contrast, X rays are attenuated by the higher atomic number elements and are more commonly used to image objects containing inorganic materials. Neutron radioscopic images of burning cigarettes under both static and dynamic smoking conditions were analyzed with a video image processor to measure the changes occurring in the images. These changes were related to the actual mass changes occurring in the cigarette rod during the burning process. Thus, the neutron images could be used to determine the deposition, movement and evaporation of pyrolysis products in the cigarette rod. In addition, it was found that the experimental data could be used to calculate the mass loss rate of a burning cigarette. While the mass loss rate of a smoldering cigarette can be measured with a balance, neutron radioscopy can determine it under dynamic smoking conditions. The results of this study along with background information on neutron radioscopy, calibration methods and the image processing program will be presented.