Overview
ISO 2884-2:2003 - "Paints and varnishes - Determination of viscosity using rotary viscometers - Part 2" - defines a standard procedure for measuring the viscosity of paints, varnishes and related products (up to 34 Pa·s) using disc or ball rotary viscometers operated at a specified speed. The method is intended primarily for production and thinning control and is suitable for both laboratory and factory environments.
Key topics and technical requirements
- Scope: Viscosity measurement for products up to 34 Pa·s; mainly for production monitoring and thinning.
- Apparatus essentials:
- Rotary viscometer (digital or analogue) operating at 562 rpm ± 2%.
- Disc spindle (type 1) for viscosities up to 1.5 Pa·s (avg. shear ≈ 200 s⁻¹).
- Ball spindles (types 2 and 3) for viscosities up to 6.5 Pa·s and 34 Pa·s (avg. shear ≈ 44 s⁻¹ and 20 s⁻¹).
- Standard 250 ml container (nominal internal diameter 74 mm) - use the same can size when comparing samples.
- Temperature-control device to maintain (23 ± 0.3) °C (procedure typically at 23 ± 0.5 °C).
- Calibrated thermometer (±0.3 °C) and calibration fluids with certified Newtonian viscosities.
- Procedure highlights:
- Sampling and sample prep per ISO 15528 and ISO 1513; optional sieving (125 µm) if required.
- Calibrate/check instrument using three reference fluids at test temperature; readings must be within ±5% of certified values.
- Ensure no air bubbles, allow thermal equilibrium, take readings at operating speed, and clean spindles after each run.
- For thixotropic materials record both initial and final readings.
- Results & reporting: Express viscosity in Pa·s (1 Pa·s = 10 poise). Test report must include apparatus type, calibration dates, container dimensions, temperature, any deviations, thixotropic behavior, and operator identity.
- Precision: No precision data included in this edition.
Applications and users
ISO 2884-2 is practical for:
- Quality control laboratories in paint, varnish and coatings manufacturing
- Production lines monitoring viscosity during formulation and thinning
- R&D and formulation teams validating process viscosity targets
- Suppliers and contract labs performing routine viscosity checks
Keywords: ISO 2884-2:2003, viscosity determination, rotary viscometer, disc viscometer, ball viscometer, paints and varnishes, viscosity measurement, production thinning, spindle calibration.
Related standards
This standard ensures consistent, repeatable viscosity measurements for production control and reliable communication of results across suppliers and customers.