ASTM D6616 - Viscosity at High Shear Rate by Tapered Bearing Simulator Viscometer at 100 °C
Signiﬁcance and Use
5.1 Viscosity at the shear rate and temperature of this test method is thought to be particularly representative of bearing conditions in large medium speed reciprocating engines as well as automotive and heavy duty engines operating in this temperature regime.
5.2 The importance of viscosity under these conditions has been stressed in railroad speciﬁcations.
5.3 For other industry needs this method may also be run at 80 °C by using different crossover calibration oils available from the manufacturer. No precision has been determined at this temperature. The equipment is also used at higher temperatures as shown in Test Method D4683 and CEC L-36-90 (also referenced from IP 370).
1.1 This test method covers the laboratory determination of the viscosity of engine oils at 100 °C and 1·106s–1 using the Tapered Bearing Simulator (TBS) viscometer.
NOTE 1—This test method is similar to Test Method D4683 which uses the same TBS viscometer to measure high shear viscosity at 150 °C.
1.2 The Newtonian calibration oils used to establish this test method range from approximately 5 mPa·s (cP) to 12 mPa·s (cP) at 100 °C and either the manual or automated protocol was used by each participant in developing the precision statement. The viscosity range of the test method at this temperature is from 1 mPa·s (cP) to above 25 mPa·s (cP), depending on the model of TBS.
1.3 The non-Newtonian reference oil used to establish the shear rate of 1·106s–1 for this test method has a viscosity of approximately 10 mPa·s at 100 °C.
1.4 Application to petroleum products other than engine oil has not been determined in preparing the viscometric information for this test method.
Extracted, with permission, from ASTM D6616-21 - Viscosity at High Shear Rate by Tapered Bearing Simulator Viscometer at 100 °C, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be purchased from ASTM International, astm.org