granulomer

Granulomer, also spelled granulometer in some contexts, is an instrument or method used to determine granulometry, the size distribution of particles in a granular material. The term can denote either a physical device that separates particles by size or the analytical process used to derive a size distribution from a sample. Granulometry is widely used in geology, soil science, pharmaceuticals, ceramics, and civil engineering.

There are several approaches to granulometry. Sieve-based granulometry uses a stack of sieves with standardized openings; the sample is dry or wet and shaken, and the mass retained on each sieve is measured to construct a size distribution. Sedimentation-based granulometry relies on particle settling in a liquid, applying Stokes’ law to relate settling velocity to diameter, and deriving distribution from time-resolved measurements. Laser diffraction granulometry employs light scattering to estimate particle sizes over a broad range and is common for liquids and slurries. Each method has specific suitability depending on particle size, shape, and dispersion.

Applications typically include characterizing soils and sands, powders in manufacturing, cement and concrete admixtures, ceramics, and pharmaceutical granules. Preparation steps—such as adequate dispersion, removal of agglomerates, and representative sampling—significantly influence results. Reported data often include cumulative and differential size distributions and characteristic percentiles such as d10, d50, and d90.

See also granulometry, sieve analysis, hydrometer method, laser diffraction.