3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 automated viscometer, n-apparatus which, in part or in whole, has mechanized one or more of the procedural steps indicated in Section 11 or 12 without changing the principle or technique of the basic manual apparatus. The essential elements of the apparatus in respect to dimensions, design, and operational characteristics are the same as those of the manual method.
3.1.1.1 Discussion - Automated viscometers have the capability to mimic some operation of the test method while reducing or removing the need for manual intervention or interpretation. Apparatus which determine kinematic viscosity by physical techniques that are different than those used in this test method are not considered to be Automated Viscometers.
3.1.2 density, n-the mass per unit volume of a substance at a given temperature.
3.1.3 dynamic viscosity, n-the ratio between the applied shear stress and rate of shear of a liquid.
3.1.3.1 Discussion - It is sometimes called the coefficient of dynamic viscosity or, simply, viscosity. Thus dynamic viscosity is a measure of the resistance to flow or deformation of a liquid.
3.1.3.2 Discussion - The term dynamic viscosity can also be used in a different context to denote a frequency-dependent quantity in which shear stress and shear rate have a sinusodial time dependence.
3.1.4 kinematic viscosity, n-the resistance to flow of a fluid under gravity.
3.1.4.1 Discussion - For gravity flow under a given hydrostatic head, the pressure head of a liquid is proportional to its density, ρ. For any particular viscometer, the time of flow of a fixed volume of fluid is directly proportional to its kinematic viscosity, v, where v=n/ρ, and n is the dynamic viscosity coefficient.
