Filter Pack Technique for Classifying Radioactive Aerosols by Particle Size. Part IV. Mathematical Considerations

摘要

Passing an air stream through a sequence of filters having different retentivities effects some classification of radioactive particles by size. Airborne radioactivity has been related to particle size by a system of four simultaneous linear algebraic equations in four unknowns. Each equation expresses the total radioactivity collected on a given filter in terms of the total activity for each size group and the probability for particles of that group being trapped on that filter. A preliminary set of filter pack collection data was used to determine a coefficient matrix for the system based on these probabilities. The system was then applied to new data. This procedure can be applied to a variety of filter pack constructions for relating other characteristics of atmospheric particles to particle size. (Author)