Measuring viscosity of new and used engine
oils at high shear rate and high temperature
by tapered bearing simulator viscometer at
150 C - Test method
(First revision)
1.1 This test method covers the laboratory determination of
the viscosity of engine oils at 150 °C and 1.0·106 s−1 using a
viscometer having a slightly tapered rotor and stator called the
Tapered Bearing Simulator (TBS) Viscometer.2
1.2 The Newtonian calibration oils used to establish this test
method range from approximately 1.2 mPa·s to 7.7 mPa·s at
150 °C. The precision has only been determined for the
viscosity range 1.47 mPa·s to 5.09 mPa·s at 150 °C for the
materials listed in the precision section.
1.3 The non-Newtonian reference oil used to establish the
shear rate of 1.0·106 s−1 for this test method has a viscosity
closely held to 3.55 mPa·s at 150 °C by using the absolute
viscometry of the TBS.
1.4 Manual, semi-automated, and fully automated TBS
viscometers were used in developing the precision statement
for this test method.
1.5 Application to petroleum products such as base oils and
formulated engine oils was determined in preparing the viscometric
information for this test method.
1.6 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
standard.
1.6.1 This test method uses the milliPascal·second (mPa·s)
as the unit of viscosity. This unit is equivalent to the centipoise
(cP).
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate
safety and health practices and determine the applicability
of regulatory limitations prior to use.
