SIST EN ISO 2811-3:2024 PDF

Overview - EN ISO 2811-3:2023 (Oscillation method for density)

EN ISO 2811-3:2023 specifies an oscillation method for determining the density of paints, varnishes and related products. The method uses a vibrating U‑tube (glass or stainless steel) whose resonance frequency changes with the mass of the filled tube. It is suitable for all material forms, including paste-like coatings, and - when a pressure‑resistant apparatus is used - can also be applied to aerosols. The standard replaces EN ISO 2811-3:2011 and aligns with ISO 2811-3:2023.

Key topics and technical requirements

• Principle: Density is derived from the resonance period (T) of a clamped, oscillating U‑tube; some instruments display density directly.
• Apparatus: U‑tube oscillator, thermometer (±0.2 °C), temperature-controlled chamber, disposable syringe. Instruments may show period or compute density internally.
• Temperature control: Tests are carried out at (23.0 ± 0.5) °C (other agreed temperatures possible). Sample, tube and oscillator must be conditioned and maintained within ±0.5 °C during measurement.
• Sampling and sample prep: Follow ISO 15528 (sampling) and ISO 1513 (examination/preparation) for representative and prepared test samples.
• De‑aeration: To ensure reproducible results, samples shall be de‑aerated before measurement (e.g. short high‑shear mixing for waterborne matrices was found suitable).
• Measurement practice:
  • If reading period T: take ≥3 readings of T and ≥2 temperatures; T values should agree within 0.0001 ms.
  • If reading density directly: take ≥3 density and ≥2 temperature readings; density values should agree within 0.0002 g·cm‑3.
  • Avoid air bubbles and ensure the display indicates air density before and after tests.
• Calculation and calibration: When T is measured, density is calculated using apparatus constants A and B (Annex A describes calibration). Annex B provides density values for damp air and air‑free water; Annex C covers temperature corrections.
• Precision and reporting: The standard includes repeatability and reproducibility considerations and a defined test report format.

Applications - who uses EN ISO 2811-3:2023

• Quality control laboratories in coatings and varnish manufacturing
• R&D teams validating formulation density, solids content and filling properties
• Contract testing and certification bodies
• Aerosol product testing when using pressure‑resistant oscillation apparatus
• Production engineers controlling process dosing and mixing where accurate density data are required

Related standards and keywords

• Normative references: ISO 1513, ISO 15528; part of the ISO 2811 series for paints and varnishes.
• SEO keywords: EN ISO 2811-3:2023, density determination, oscillation method, paints and varnishes, U‑tube oscillator, density of coatings, de‑aeration, temperature control, apparatus calibration.

This standard provides a robust, reproducible method for measuring coating density that supports QC, formulation development and regulatory testing across the coatings industry.