Overview
EN ISO 2811-2:2011 - "Paints and varnishes - Determination of density - Part 2: Immersed body (plummet) method" is a CEN-adopted ISO standard that specifies a practical method to determine the density of paints, varnishes and related products using an immersed round body (plummet). The method is intended for low- to medium-viscosity products and is particularly suitable for production control and routine quality checks.
Key topics and technical requirements
- Principle: Based on Archimedes’ principle. Density ρ is obtained from the change in balance reading before and after immersion of the plummet: ρ = (m1 − m2) / Vt, where m1 = mass of vessel/sample before immersion, m2 = mass after immersion and Vt = calibrated plummet volume at test temperature.
- Test temperature: Standard reference temperature is 23.0 ± 0.5 °C (conditioning and test temperature must be controlled; temperature variation should not exceed 0.5 °C).
- Apparatus:
- Plummets (non-corrodible metal) commonly 10 cm³ or 100 cm³, marked with volume and reference data.
- Analytical balance with ±0.01 g (10 mg) readability.
- Thermometer (±0.2 °C), temperature-controlled chamber, tripod/retort stand and suitable vessels.
- Sampling and preparation: Follow ISO 15528 (sampling) and ISO 1513 (sample examination and preparation).
- Procedure:
- Single determination on a fresh sample (duplicate no longer required).
- Two procedural variants: a general procedure and a variant for fast-evaporating solvent products to avoid solvent loss during weighing.
- Plummet volume must be calibrated (guidance/example in annex).
- Precision:
- Repeatability (r) and reproducibility (R) limits are provided:
- Solvents: r = 0.002 g/cm³, R = 0.004 g/cm³
- Coating materials (10 cm³ plummet): r = 0.011 g/cm³, R = 0.030 g/cm³
- Coating materials (100 cm³ plummet): r = 0.003 g/cm³, R = 0.004 g/cm³
Applications
- Production control and filling-line calibration: quick, repeatable density checks for process control.
- Quality assurance and batch verification: routine monitoring of paint and varnish density to ensure product consistency.
- Incoming raw-material checks: verify density of solvents and resin-based components.
Who should use this standard
- Paint and varnish manufacturers and formulators
- QC/QA laboratories in coatings industry
- Filling and packaging engineers calibrating volumetric equipment
- Laboratories performing routine density testing for regulatory or contractual compliance
Related standards
Keywords: EN ISO 2811-2:2011, paints and varnishes, density determination, immersed body plummet method, production control, plummet, analytical balance, test temperature.