Year of publication: 2007
For a slide bearing or gear design, the specification of viscosity at 40° C and 100° C or the calculation of viscosities at other temperatures on the basis of the viscosity index (VI) is usually not sufficiently informative.
Often equipment is operated under widely varying climatic conditions or at different temperatures. At cold start, the oil is viscous. Later, when the operating temperature is reached, it is thin-bodied. To design bearings, lubrication holes, pump pressures, tooth widths, etc., a designer then needs the actual, dynamic viscosity at precisely these limit temperatures. Often, the approximate values determined using calculation methods based on Walther's straight line are too inaccurate.
To create the viscosity-temperature profile, measurements are carried out at intervals of 10° C in the temperature range from -30° C to +110° C. The results of these measurements are available in tabular form on the one hand and in graphical form on the other hand, both on the OELCHECK laboratory report and at https://lab.report.