Overview
EN ISO 3219-1:2021 - "Rheology - Part 1: Vocabulary and symbols for rotational and oscillatory rheometry (ISO 3219-1:2021)" - defines general terms, definitions and symbols used in rotational and oscillatory rheometry. This harmonized CEN/ISO document consolidates standardized terminology for rheology measurements (rotational tests, oscillatory tests) used across paints, varnishes, polymers and related materials. The part contains an alphabetical index and a table of symbols to support consistent reporting and interpretation of rheological data.
Key topics and requirements
- Scope: Provides general terms and symbol definitions for rotational and oscillatory rheometry; further, more specific terms appear in other parts of the ISO 3219 series.
- Terminology: Defines key rheology vocabulary such as shear modulus (G), shear loss modulus (G''), complex shear modulus (G*), complex shear viscosity (η*), dynamic viscosity (η'), loss angle (δ), loss factor (tan δ), linear viscoelastic range (LVR), Newtonian/non‑Newtonian behaviour, rheopexy, and more.
- Test types and parameters: Covers definitions for oscillatory tests (controlled strain or controlled stress), rotational tests (controlled rate or controlled stress), frequency sweep, amplitude sweep, continuous ramp, angular frequency/velocity, rotational speed and related units.
- Symbols and units: Provides a standardized symbol set (including units like Pa, Pa·s, Hz, rad·s‑1) to ensure uniform notation in test methods, reports and instrument outputs.
- Administrative notes: No normative references; supersedes earlier editions and aligns with ISO and CEN editorial practices.
Practical applications
- Ensures clear, unambiguous reporting of rheological measurements in research, quality control and regulatory documentation.
- Supports instrument manufacturers and software developers in using consistent symbol sets and parameter names for rotational and oscillatory rheometers.
- Helps laboratories and testing facilities maintain method comparability, reproducibility and conformity with international standards when measuring viscosity, viscoelasticity and flow curves.
- Useful in industries such as coatings, paints, adhesives, polymers, plastics and cosmetics where rheological characterization is critical to product performance.
Who uses this standard
- Rheologists, materials scientists and laboratory technicians
- Instrument and sensor manufacturers (rheometers)
- Quality assurance and regulatory teams in coatings, polymers and related sectors
- Standards developers and test method authors
Related standards
- Other parts of the ISO 3219 series (e.g., ISO 3219-2 for general principles and absolute measuring geometries)
- The publication is published as EN ISO 3219-1:2021 at CEN level and replaces earlier ISO/EN editions.
Keywords: EN ISO 3219-1:2021, rheology vocabulary, rotational rheometry, oscillatory rheometry, shear modulus, complex viscosity, LVR, frequency sweep, amplitude sweep, rheometry symbols.
