Here at Oil Analysis Laboratories, we have a state-of-the-art robotic bath system and. The time taken for the oil to run through the tube is recorded and the data is collected for analysis. What Is Viscosity Index Not all oil types respond the same to temperature changes. That is why we say kinematic viscosity represents the rate of oil flow. Established to represent a universally accepted grading system (e.g. The test involves dropping the oil into a glass tube that runs through a Houillon kinematic viscosity bath heated at 40 or 100 C depending on the oil type. The kinematic viscosity of oil indicates how the oil behaves when impacted by gravity. Fluid Characteristics Chart Table: for Vapour Pressure kPa, Density, Kinematic Viscosity at specified temperature. International Standards Organization (ISO) grades for hydraulic fluids and industrial gear lubricants. SAE 75W-90)Īmerican Gear Manufacturers Association (AGMA) grades for industrial gear lubricants (e.g. Society of Automotive Engineers (SAE) grades for automotive gear oils (e.g. Society of Automotive Engineers (SAE) grades for automotive motor oils (e.g. More specific classifications give us a better idea of how fluids move, but you’ve likely seen at least a few different ways to designate viscosity: However, these terms are general and difficult to measure. Terms such as thick, heavy or high suggest a fluid with strong resistance to flow, such as honey. Some of the informal terms used to describe the viscosity of a relatively free-flowing fluid, such as water, include thin, light and low. A copy of the complete standard may be purchased from ASTM International, astm.Viscosity, defined as a fluid’s resistance to flow, is one of the most important characteristics of a lubricant. For user reference, 1 mm2/s = 10-6m 2/s = 1 cSt.Įxtracted, with permission, from ASTM D2270-10 - Calculating Viscosity Index from Kinematic Viscosity at 40 ☌ and 100 ☌, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. No other units of measurement are included in this standard.ġ.4.1 The values stated in SI units are to be regarded as the standard.
#Kinematic viscosity of engine oil iso#
The determination of the kinematic viscosity of a petroleum product shall be carried out in accordance with Test Methods D445, D7042, IP 71, or ISO 3104.ġ.3.1 If Viscosity Index calculated for a given sample using kinematic viscosity measurements from different test methods are in disagreement, the values calculated from Test Method D445 measurements shall be accepted.ġ.4 The values stated in SI units are to be regarded as standard. See Test Method D341, Annex A1.ġ.3 The kinematic viscosity values are determined with reference to a value of 1.0034 mm2/s at 20.00 ☌ for distilled water. Such viscosity index data may be considered as suitable for information only and not for specification purposes. The following instruments were selected to measure: a mid-FTIR spectrophotometer, a microchannel viscometer, and a Stabinger viscometer. Equations are provided for calculating viscosity index for petroleum products having kinematic viscosities above 70 mm2/s at 100 ☌.ġ.2.1 In cases where kinematic viscosity data are not available at temperatures of 40 ☌ and 100 ☌, an estimate may be made of the viscosity index by calculating the kinematic viscosity at temperatures of 40 ☌ and 100 ☌ from data obtained at other temperatures. The aim of this paper is to compare the results of kinematic viscosity of lubricating oils measurements at 40 C, obtained with three different rapid evaluation devices, and the standardized method using an Ubbelohde Capillary viscometer. Table 1 given in this practice applies to petroleum products with kinematic viscosities between 2 mm2/s and 70 mm2/s at 100 ☌. NOTE 1: The results obtained from the calculation of VI from kinematic viscosities determined at 40 ☌ and 100 ☌ are virtually the same as those obtained from the former VI system using kinematic viscosities determined at 37.78 ☌ and 98.89 ☌.ġ.2 This practice does not apply to petroleum products with kinematic viscosities less than 2.0 mm2/s at 100 ☌. 4.1 The viscosity index is a widely used and accepted measure of the variation in kinematic viscosity due to changes in the temperature of a petroleum product between 40 ☌ and 100 ☌.Ĥ.2 A higher viscosity index indicates a smaller decrease in kinematic viscosity with increasing temperature of the lubricant.Ĥ.3 The viscosity index is used in practice as a single number indicating temperature dependence of kinematic viscosity.Ĥ.4 Viscosity Index is sometimes used to characterize base oils for purposes of establishing engine testing requirements for engine oil performance categories.6ġ.1 This practice2 covers the procedures for calculating the viscosity index of petroleum products, such as lubricating oils, and related materials from their kinematic viscosities at 40 ☌ and 100 ☌.
0 kommentar(er)
