Meaning and use
5.1 Many petroleum products and some non-petroleum materials are used as lubricants and the correct operation of the equipment depends on the appropriate viscosity of the liquid used. In addition, the viscosity of many petroleum fuels is important for estimating better storage, handling and operating conditions. Therefore, the accurate determination of viscosity is important for many product specifications.

Radius
1.1 This test method specifies a procedure for determining the kinematic viscosity ν of transparent and opaque liquid petroleum products by measuring the time of a given volume of liquid in a gravity-over-calibrated glass capillary viscometer. The dynamic viscosity η can be obtained by multiplying the kinematic viscosity ν by the density ρ of the liquid.

Note 1: For measurement of kinematic viscosity and viscosity of asphalt, see also test methods D2170 and D2171.

Note 2: ISO 3104 corresponds to test method D445-03.

ASTM D445-2018 Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (Calculation of Dynamic Viscosity)

1.2 The results obtained from this test method depend on the behavior of the sample and are intended to be applied to liquids where the shear stress and shear rate are proportional (Newtonian flow behavior). However, if the viscosity varies significantly with the shear rate, different results can be obtained from viscometers with different capillary diameters. Procedure and precision values have been included for residual fuel oils, which exhibit non-Newtonian behavior in some cases.

1.3 The test method covers the kinematic viscosity range from 0.2 mm2/s to 300,000 mm2/s (see Table A1.1) at all temperatures (see 6.3 and 6.4). Accuracy is determined only for these materials, kinematic viscosity ranges, and temperatures, as indicated in the footnote in the accuracy section.

1.4 Values expressed in SI units shall be regarded as standard values. The SI unit used in the kinematic viscosity test method is mm2/s, and the SI unit used in the dynamic viscosity test method is mPa·s. For user reference, 1 mm2/s = 10-6 m2/s = 1 cSt and 1 mPa·s = 1 cP = 0.001 Pa·s.

1.5 Warning – Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical problems. Mercury or its vapors have been shown to be harmful to health and corrosive to materials. Be careful when handling mercury and products containing mercury. For more information, refer to the applicable Product Safety Data Sheet (SDS). Local or national laws may prohibit the sale of mercury or mercury-containing products, or both. Users need to determine the legality of the sale in their location.

ASTM D445-2018 Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (Calculation of Dynamic Viscosity)

1.6 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

1.7 This international standard is based on internationally recognized standardization principles established in the Decision on Principles for the Development of International Standards, Guidelines and Recommendations issued by the Committee on Technical Barriers to Trade of the World Trade Organization.