Overview
EN ISO 3219-2:2021 - "Rheology - Part 2: General principles of rotational and oscillatory rheometry (ISO 3219-2:2021)" is a CEN-adopted international standard that specifies the general principles for performing rotational and oscillatory rheometry. The document defines measurement concepts, symbols and terminology, and the main elements of a measuring assembly. Detailed information is provided in Annex A, and further background is covered in other parts of the ISO 3219 series (in preparation).
Keywords: ISO 3219-2:2021, rheology standard, rotational rheometry, oscillatory rheometry, measuring geometries, viscosity measurement.
Key topics and technical requirements
The standard sets out foundational requirements and definitions used across rotational and oscillatory rheometry:
- Scope and normative references: builds on ISO 3219-1 (terms and definitions).
- Terms and definitions: clear definitions such as measuring gap, gap width, no-slip condition, wall slip, absolute and relative measuring geometries.
- Symbols and units: standardized symbols for shear stress, shear strain, complex viscosity, complex shear modulus, torque, angular velocity and more.
- Measuring principles:
- Rotational rheometry: torque-angular velocity relationships and viscosity evaluation.
- Oscillatory rheometry: strain, stress, complex modulus and phase relationships.
- Measuring assembly and accessories:
- Temperature control systems and thermal covers.
- Measuring geometries: absolute geometries (e.g., cone‑plate, coaxial cylinders) and relative geometries (including plate‑plate), with guidance on gap width and flow-field coefficients.
- Optional items: covers, solvent traps, stepped plates and others.
- Annex A (informative): information on rheometry and flow-field patterns for practical understanding.
Practical applications
This standard is used to ensure consistency, reproducibility and comparability of rheological measurements in:
- Quality control and R&D for polymers, paints, coatings, varnishes and other complex fluids.
- Characterization of viscosity, shear stress, shear rate, storage and loss moduli using rotational and oscillatory tests.
- Instrument selection, method development and reporting of rheological data.
Keywords: viscosity measurement, shear rate, complex modulus, rheometer calibration, measuring geometry.
Who should use this standard
- Test laboratories and quality control teams in polymer, coatings and chemical industries.
- Rheometer manufacturers and instrument engineers.
- Research scientists performing rheological characterization.
- Standards committees and regulatory bodies harmonizing test methods.
Related standards
- ISO 3219-1 (terms and definitions) - normative reference.
- Additional parts of the ISO 3219 series (under development) provide expanded test methods and background.
This standard provides the essential, standardized framework for rotational and oscillatory rheometry, improving measurement reliability across industry and research.
