The ratio of the difference between the viscosities of solution and solvent to the
viscosity of the solvent, i.e.

,
where

is the
viscosity of the solution and

is the
viscosity of the solvent. The use of the term '
specific viscosity' for this quantity is discouraged, since the
relative viscosity increment does not have the attributes of a specific quantity.
Source:
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.