Title: apparent viscosity
Long Title: IUPAC Gold Book - apparent viscosity
DOI: 10.1351/goldbook.A00420
Status: current

Definition
The ratio of stress to rate of strain, calculated from measurements of forces and velocities as though the liquid were Newtonian. If the liquid is actually non-Newtonian, the apparent viscosity depends on the type and dimensions of the apparatus used.

Related Terms
- strain: https://goldbook.iupac.org//terms/view/S06037
- viscosity: https://goldbook.iupac.org//terms/view/V06627

Source
- PAC, 1979, 51, 1213. 'Terminology and Symbols in Colloid and Surface Chemistry Part 1.13. Definitions, Terminology and Symbols for Rheological Properties' on page 1217 (https://doi.org/10.1351/pac197951051213)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/A00420/html
- json: https://goldbook.iupac.org/terms/view/A00420/json
- xml: https://goldbook.iupac.org/terms/view/A00420/xml

Citation: Citation: 'apparent viscosity' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.A00420
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-04-18T13:26:22+00:00