Overview
EN ISO 2811-4:2011 - "Paints and varnishes - Determination of density - Part 4: Pressure cup method" is a CEN-adopted ISO standard that specifies a laboratory pressure cup method to measure the density of paints, varnishes and related products. The method is intended for aerated products (for example, many emulsion paints that trap small air bubbles) but is not suitable for textured paints containing coarse particles. Results are reported in grams per cubic centimetre (g/cm³) at a defined test temperature.
Key topics and technical requirements
- Principle: A known-volume cylindrical pressure cup (nominal 100 cm³) compresses the sample to reduce errors from entrapped air; density is calculated from mass difference and calibrated cup volume.
- Test temperature: Carry out at (23.0 ± 0.5) °C (other agreed temperatures may be used); sample and apparatus must be conditioned and temperature variation ≤ 0.5 °C.
- Apparatus:
- Pressure cup with screw-driven piston and pressure-release cap (release at ~1.0 ± 0.1 MPa).
- Balance accurate to 10 mg; thermometer accurate to 0.2 °C; temperature-controlled chamber.
- Procedure: Single determination on a fresh, prepared sample. Fill cup, apply pressure until calibration collar stops and excess liquid is expelled, clean and weigh.
- Calibration & verification: Periodic calibration of cup volume (Annex A) using pure water; pressure-release and volume checks required.
- Reporting & precision:
- Report density to the nearest 0.001 g/cm³.
- Include cup identification, test temperature, any deviations and anomalies.
- Repeatability limit (r) for non-aerated materials: 0.005 g/cm³.
- Referenced standards: ISO 1513 (sample prep), ISO 3696 (water purity), ISO 15528 (sampling).
Applications and users
This standard is practical for:
- Quality control and R&D laboratories in paint and coatings manufacturing.
- Formulation engineers and technical service teams assessing filling, packing and dosing operations.
- Independent testing laboratories required to provide traceable density measurements for product specifications.
- Engineers controlling filling machines, where uncorrected density values are used for machine calibration.
Typical uses:
- Verifying batch-to-batch density for volumetric filling.
- Comparing densities of aerated emulsion paints.
- Providing standardized density data for product data sheets and regulatory reporting.
Related standards
- EN ISO 2811 series:
- Part 1: Pyknometer method
- Part 2: Immersed body (plummet) method
- Part 3: Oscillation method
- Part 4: Pressure cup method (this document)
- Normative references: ISO 1513, ISO 3696, ISO 15528
Keywords: EN ISO 2811-4:2011, pressure cup method, density measurement, paints and varnishes, aerated paints, emulsion paints, laboratory testing, calibration, filling-machine control.