versión On-line ISSN 1678-992X
ELIAS, Elimoel Abraão; BACCHI, Osny Oliveira Santos y REICHARDT, Klaus. EXACT EQUATIONS FOR SOIL PARTICLE-SIZE ANALYSIS BY GAMMA-RAY ATTENUATION. Sci. agric. [online]. 1999, vol.56, n.1, pp. 93-96. ISSN 1678-992X. http://dx.doi.org/10.1590/S0103-90161999000100014.
Soil particle-size analysis by gamma-ray attenuation was first suggested in 1992 and improved in 1997 by diminishing the measurement time and adapting it for automation. It is here demonstrated that when the mass attenuation coefficient mw and the density Dw are replaced by ms and Ds (where the subscripts w and s stand for water and solution) in the approximate equations used to estimate the concentration of suspended particles, they become exact. The demonstration is based by treating the dispersant and water solution as one single medium, instead of treating them as two media. In this way, six variables are reduced to only three. Physical considerations suggest that the precision in this analysis could be improved if other types of solutions and of photon energies would be used, so that the attenuation by the particles would differ more significantly from the attenuation by the solution.
Palabras clave : granulometry; soil mechanical analysis; soil texture; gamma attenuation.