Overview
ISO 11508:2017 - Soil quality - Determination of particle density specifies laboratory procedures to determine the particle density of soils from the mass and volume of soil particles. The standard defines two complementary methods:
- Fine soil (< 2 mm) - pycnometer method (wetting, deaeration, and mass/volume calculation).
- Gravel and stones (> 2 mm) - weighing-in-air and weighing-in-water method for coarse particles.
Particle density obtained by ISO 11508:2017 is used together with dry bulk density (see ISO 11272) to calculate the proportion of solids and soil porosity.
Key topics and technical requirements
- Scope and definitions: particle density = oven-dry mass of solid particles divided by their volume (internal pores included; interparticle voids excluded).
- Two measurement procedures:
- Fine soil (clause 4.1): use a calibrated pycnometer (20–50 cm3 recommended), thermometer (±0.1 °C), vacuum desiccator, laboratory balance (0.1 mg accuracy), and a 2 mm sieve. Determine air‑dried mass, deaerate with boiled/cooled water, measure masses, and compute density using the density of water at the measured temperature.
- Gravel/stones (clause 4.2): clean and oven‑dry coarse material (105 ± 2 °C), weigh in air and while submerged (using a suspended frame setup), and calculate density from displaced water mass.
- Temperature correction: clause 4.3 provides a coefficient and method to convert measured densities to a unified reference temperature (20 °C) using Table A.1 (density of water at different temperatures).
- Mean particle density: clause 4.4 gives a mass‑weighted formula to combine densities of fine and coarse fractions into a total soil particle density.
- Precision indicators: typical standard deviations reported - fine soil ~0.02–0.03 g/cm3; gravel/stones ~0.01 g/cm3.
- Reporting: test report must reference ISO 11508, identify the sample, state the method used, results, and any deviations or influencing factors.
Applications and practical value
- Calculation of soil porosity and solid fraction when combined with dry bulk density (ISO 11272).
- Important for soil science, agronomy, environmental assessments, geotechnical investigations, landfill and civil engineering projects where accurate solid/void partitioning influences water retention, compaction and transport modelling.
- Useful in research labs and commercial testing facilities needing standardized, reproducible particle density data for soils and granular materials.
Who should use this standard
- Soil testing laboratories and quality-control facilities
- Environmental and agricultural consultants
- Geotechnical and civil engineers
- Researchers in soil physics, hydrology and land remediation
Related standards
- ISO 11272 - Dry bulk density of soils (porosity calculations)
- ISO 11461 - Determination of soil water content as a volume fraction (gravimetric method)
- ISO 565 - Test sieves (2 mm sieve reference)
- Annex A of ISO 11508 provides the density-of-water table and coefficients for temperature corrections.
