Overview
EN ISO 11508:2017 - Soil quality: Determination of particle density (ISO 11508:2017) specifies two validated laboratory methods to determine the particle density of soils from measured mass and particle volume. Particle density (mass of oven‑dry solids divided by particle volume, including internal pores but excluding inter-particle voids) is a critical property used alongside dry bulk density to calculate soil porosity and the proportion of solids in a soil layer.
This European adoption of ISO 11508 (approved November 2017) is intended for environmental and geotechnical laboratories, research institutes and practitioners performing soil characterization for agriculture, remediation, civil engineering and environmental monitoring.
Key topics and technical requirements
- Two methods by particle size
- Method 4.1 - Fine soil (< 2 mm): Pycnometer method. Key steps include sieving (<2 mm), air‑drying, determination of reference water content, wetting and de‑aeration in a pycnometer, temperature control and use of water density to compute particle density.
- Method 4.2 - Gravel and stones (> 2 mm): Immersion/buoyancy method for porous and non‑porous coarse material using a suspended frame/dish; cleaning (e.g., sodium hexametaphosphate), oven drying (105 ± 2 °C) and de‑aeration of immersed water are required.
- Apparatus and accuracy requirements
- Thermometer accurate to 0.1 °C, laboratory balances (fine‑soil balance to 0.1 mg), calibrated pycnometer (20–50 cm3 recommended), vacuum desiccator with self‑indicating desiccant, ISO 565 conforming 2 mm sieve.
- Calculations & reporting
- Use measured masses and the density of water at the measured temperature (Annex A) to calculate particle density. The standard includes procedures for unified reference temperature and calculation of mean particle density. Typical inter‑laboratory SD for fine soils noted (~0.02–0.03 g·cm‑3).
- Quality and documentation
- Requirements for sampling, de‑aeration, temperature control and test reporting to ensure repeatability and traceability.
Applications and users
- Environmental laboratories performing soil quality assessments, contaminated land investigations and remediation monitoring.
- Agricultural and pedological research requiring accurate porosity and solid fraction calculations.
- Geotechnical and civil engineering projects needing reliable soil physical properties for foundation, compaction and drainage design.
- Regulatory bodies and consultants standardizing soil testing protocols and reporting.
Related standards
- ISO 11272 - Dry bulk density and porosity calculations (used together with particle density).
- ISO 565 - Test sieves (aperture sizes).
- ISO 11461 - Determination of soil water content (gravimetric method).
- ISO/TC 190 (Soil quality) is the responsible technical body.
Keywords: EN ISO 11508:2017, particle density, soil quality, pycnometer, soil testing standard, porosity calculation, ISO 11508.
