Overview
EN ISO 11272:2017 - Soil quality: Determination of dry bulk density specifies standardized laboratory and field methods to determine the dry bulk density of soils. The standard defines three accepted approaches - the core method, excavation (sand/water replacement) method, and the clod method - all based on determining the oven‑dry mass and the sample volume to calculate dry bulk density (oven-dry mass divided by sample volume).
Key topics and requirements
- Three methods covered
- Core method (4.1): Use thin‑walled metal core sample holders (100–400 cm³) driven into stoneless or slightly stony soils. Volume is known from the sampler.
- Excavation method (4.2): Determine sample volume in situ by replacing the excavated volume (e.g., sand/water replacement) - described for field and lab procedures.
- Clod method (4.4): Determine the volume of an intact soil clod by immersion/volume displacement techniques.
- Essential apparatus
- Oven, heated and ventilated, capable of (105 ± 2) °C.
- Desiccator for cooling samples.
- Laboratory balance capable of weighing to an accuracy of 1/1 000 of the measured value.
- Metal core samplers (with steel cap and driver).
- Sampling and drying
- Samples dried to constant mass (note: constant mass commonly reached after ~48 h).
- Control mass criterion: successive cooled weighings at 4 h intervals differing by ≤0.01% of original mass.
- Take at least six core samples per soil layer when using the core method.
- Definitions and units
- Dry bulk density (ρd): oven‑dry mass of solids divided by bulk volume (includes pores). Preferred SI unit: kg·m⁻³; g·cm⁻³ also common (1 g·cm⁻³ = 1000 kg·m⁻³).
- Special cases
- Swell/shrink soils (clays, peats) should be sampled in multiple moisture states (field capacity, saturation, wilting point). If sampling with core is impractical, use substitute or excavation methods (see Clauses 4.2–4.3).
Applications and users
- Practical uses
- Soil structure and porosity assessment.
- Calculating solids content and converting contaminant concentrations between mass/volume and mass/mass.
- Agricultural soil management, geotechnical site investigation, environmental monitoring, contaminated site assessment, and research.
- Who uses this standard
- Soil testing laboratories, agronomists, geotechnical and environmental engineers, consultants, academic researchers, and regulatory bodies.
Related standards
- ISO 11508 (particle density)
- ASTM D1556, D2167, D4914, D5030 (field density/replacement methods)
- DIN 18125‑2
Keywords: EN ISO 11272:2017, dry bulk density, soil quality, core method, excavation method, clod method, oven-dry, soil porosity, soil sampling.