ISO 16065-2:2014 PDF

Overview - ISO 16065-2:2014 (Unpolarized light method)

ISO 16065-2:2014 specifies an automated optical analysis method for determining fibre length in pulps using unpolarized light. The procedure applies to all pulp types but excludes fibrous particles shorter than 0.2 mm from results. The standard defines the measurement principle, apparatus requirements, sample preparation, measurement and verification procedures, and result calculation and reporting.

Key topics and technical requirements

• Measurement principle: fibres in suspension pass through a measuring cell; an unpolarized light source produces a high‑contrast image and a detector (e.g., CCD camera) determines individual fibre lengths.
• Apparatus specs:
  • Resolution: equal to or better than 100 µm over the 0–7 mm range.
  • Accuracy: at least 0.01 mm.
  • Flow must orient fibres into a focal depth ≤ 0.5 mm and be resistant to interference from air bubbles or non‑fibrous particles > 0.2 mm.
• Sample preparation:
  • Follow appropriate disintegration (ISO 5263 series) or test never‑dried pulps where possible to avoid generating fines.
  • Recommended test mass fractions: 0.010–0.025% for softwood, 0.004–0.010% for hardwood; mixed stocks treated as hardwood.
  • Dilution water: free of non‑fibrous material and bubbles > 5 µm, evaporation residue