ISO 23581:2020 PDF

Scope: This document specifies a procedure for the determination of kinematic viscosity (ν) at 40 °C in the range from 2 mm2/s to 6 mm2/s by calculation from dynamic viscosity (η) and density (ρ) of middle distillate fuels, fatty acid methyl ester fuels (FAME) and mixtures of these using the Stabinger type viscometer. The result obtained using the procedure described in this document depends on the rheological behaviour of the sample. This document is predominantly applicable to liquids whose shear stress and shear rate are proportional (Newtonian flow behaviour). However, if the viscosity changes significantly with the shear rate, comparison with other measuring methods is only permissible at similar shear rates.

ISO 23581:2020 Referenced Document

ISO 12185 Crude petroleum, petroleum products and related products*， 2024-01-01 Update
ISO 3104 Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity and calculation of dynamic viscosity*， 2023-10-01 Update
ISO 3170 Petroleum liquids - Manual sampling
ISO 3171 Petroleum liquids; automatic pipeline sampling

2020 ISO 23581:2020 Petroleum products and related products — Determination of kinematic viscosity — Method by Stabinger type viscometer