Overview
ISO 13061-16:2017 specifies standardized test methods for the determination of volumetric swelling of wood using small clear wood specimens. The standard defines two methods - the stereometric method and the immersion method - to measure volume change between an oven‑dry state and a fully saturated state (above the fibre saturation point). Results are expressed as volumetric swelling (%) to a precision of 0.1%.
Key Topics and Requirements
- Scope: Methods for determining volumetric swelling of wood specimens (ISO 13061-16:2017).
- Principle: Measure volume at absolutely dry (oven‑dry) condition and after full water saturation; calculate percent change in volume (ΔV/Vinitial × 100).
- Two specified methods:
- Stereometric method: Volume calculated from linear dimensions (radial × tangential × longitudinal). Requires rectangular prism specimens with minimum sizes of 20 mm (radial and tangential) and 5 mm (along the grain). Marked measurement points and ring inclination ≤ 10°.
- Immersion method: Volume measured by water displacement (or mass of displaced water). Specimens may be any shape with a minimum volume of 4 cm³.
- Apparatus and tolerances:
- Oven: forced‑convection at (103 ± 2) °C for drying to constant mass.
- Measuring instruments: linear measurement accuracy 0.02 mm (stereometric).
- Balance accuracy 0.001 g; volume resolution 0.01 cm³ for immersion.
- Conditioning and checks:
- Dry to constant mass (control weighings until change ≤ 0.2%).
- Soak in distilled water at (20 ± 2) °C until dimensional/volume stability (repeat checks every 3 days).
- Discard specimens with checks or distortion.
- Reporting: Test report should reference ISO 13061-16, sampling details (ISO 3129), method used, measurement details, results (with statistical values), test date and testing organization.
Applications and Who Uses It
ISO 13061-16 is used by:
- Materials testing laboratories performing wood property characterization and quality control.
- Timber and wood‑products manufacturers assessing dimensional stability for flooring, furniture, joinery and engineered wood products.
- Researchers and R&D teams studying moisture‑related behavior, swelling anisotropy, and treatment effects.
- Standards bodies and certification agencies requiring reproducible test data for specification and compliance.
Practical uses include comparing species, evaluating treatments/coatings, validating models of hygromechanical behaviour, and ensuring product performance where moisture exposure affects dimensional stability.
Related Standards
- ISO 3129 - Sampling and preparation of small clear wood specimens (referenced).
- ISO 24294 - Timber vocabulary and relevant terms.
Keywords: ISO 13061-16:2017, volumetric swelling, wood test methods, small clear wood specimens, stereometric method, immersion method, oven‑dry, fibre saturation point.