Particle-Size Analysis of Soils Using Laser Light Scattering and X-Ray Absorption Technology

Abstract

Abstract The particle-size distribution for the fine-grained fraction of eleven soil samples was determined using four commercially available, state-of-the-art automated particle-size distribution analysis instruments. Two of the instruments operate on the principle of interaction of laser light with soil particles suspended in water in a highly agitated state, and two operate on the principle of the absorption of an X-ray beam by a suspension of soil particles settling in a quiescent column of water. The results from each instrument for each soil sample were compared to size analysis data determined by the hydrometer technique. The X-ray absorption instruments produced particle-size distributions very close to those of the hydrometer method, with the exception of soils with high mica concentrations. The laser-based instrument data did not agree as well with the hydrometer data, although for soils with significant mica contents the results were closer than the results from the X-ray absorption instruments. Based on these results, however, it appears that the automated X-ray absorption/sedimentation-based instruments show promise as alternatives or as a possible supplement for the manual hydrometer method of size analysis for soils without significant mica particle concentrations.