Particle Diameter Sorting Guide
Particle diameter sorting helps describe a mixed granular sample. It is useful in sediment studies, powder checks, screening work, and classroom analysis. This calculator turns sieve limits, retained mass, and phi percentiles into practical size values. It also gives a sorting class, so the spread of particle sizes is easier to read.
Why Diameter Matters
A single sample can contain many grain sizes. A basic average may hide that variation. The geometric mean diameter is often helpful because sieve openings work on ratio changes. It balances the upper and lower sieve limits. The phi value gives another view. It converts millimeter diameter into a logarithmic scale. Coarser grains have lower phi values. Finer grains have higher phi values.
Sorting Meaning
Sorting describes how similar the particle sizes are. A well sorted sample has grains close to one size. A poorly sorted sample has wide size variation. The inclusive graphic standard deviation uses the fifth, sixteenth, eighty fourth, and ninety fifth percentiles. These percentiles summarize both the middle spread and the tails. The result is then matched with a standard sorting name.
Practical Use
Use clean sieve data when possible. Enter the larger sieve opening as the upper limit. Enter the smaller opening as the lower limit. Add the mass retained and total mass to calculate retained percentage. Use a shape factor of one for rounded particles. Lower values can represent flatter or irregular grains. Particle count and density estimate an equivalent spherical diameter from sample volume.
Interpreting Results
Compare the geometric diameter with the volume equivalent diameter. Large differences can indicate unusual shape, counting error, or mixed material. Check the median diameter from phi fifty for central grain size. Review the sorting class before making decisions. Good data should make physical sense. Repeat measurements when results look extreme. Export the result for records, reports, or teaching notes. For mathematical work, keep units consistent. Most sediment formulas expect millimeters. Convert micrometers, centimeters, or inches before comparing phi output. Record sieve condition, sample drying method, and weighing precision. These notes help others reproduce the calculation. They also make later audits clearer and more reliable overall. This tool supports quick checks, but lab standards should guide final technical decisions.