ASTM D6616-01
(Test Method)Standard Test Method for Measuring Viscosity at High Shear Rate by Tapered Bearing Simulator Viscometer At 100°C
Standard Test Method for Measuring Viscosity at High Shear Rate by Tapered Bearing Simulator Viscometer At 100°C
SCOPE
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 D 4683 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 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.
1.5 This test method uses the milliPascal second (mPa·s) as the unit of viscosity. This unit is equivalent to the centiPoise (cP), which is shown in parentheses.
1.6 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 to determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: D 6616 – 01
Standard Test Method for
Measuring Viscosity at High Shear Rate by Tapered Bearing
Simulator Viscometer At 100°C
This standard is issued under the fixed designation D 6616; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the laboratory determination of 3.1 Definitions:
6 –1
the viscosity of engine oils at 100°C and 1•10 s using the 3.1.1 density—the mass per unit volume. In the SI, the unit
Tapered Bearing Simulator (TBS) viscometer. of density is the kilogram per cubic metre, but for practical use,
a submultiple is more convenient. The gram per cubic centi-
NOTE 1—This test method is similar to Test Method D 4683 which uses
3 3
metre is equivalent to 10 kg/m and is customarily used.
the same TBS viscometer to measure high shear viscosity at 150°C.
3.1.2 Newtonian oil or fluid—an oil or fluid that at a given
1.2 The Newtonian calibration oils used to establish this test
temperature exhibits a constant viscosity at all shear rates or
method range from approximately 5 to 12 mPa•s (cP) at 100°C
shear stresses.
and either the manual or automated protocol was used by each
3.1.3 non-Newtonian oil or fluid—an oil or fluid that exhib-
participant in developing the precision statement. The viscosity
its a viscosity that varies with changing shear stress or shear
range of the test method at this temperature is from 1 mPa•s
rate.
(cP) to above 25 mPa•s (cP), depending on the model of TBS.
3.1.4 shear rate—the velocity gradient in fluid flow. The SI
1.3 The non-Newtonian reference oil used to establish the
–1
unit for shear rate is s .
6 –1
shear rate of 1•10 s for this test method has a viscosity of
3.1.5 shear stress—the motivating force per unit area for
approximately 10 mPa•s at 100°C.
fluid flow. The area is the area under shear.
1.4 Application to petroleum products other than engine oil
3.1.6 viscosity—the ratio between the applied shear stress
has not been determined in preparing the viscometric informa-
and the rate of shear. It is sometimes called the coefficient of
tion for this test method.
dynamic viscosity. This coefficient is a measure of the resis-
1.5 This test method uses the milliPascal second (mPa•s) as
tance to flow of the liquid. In the SI, the unit of viscosity is the
the unit of viscosity. This unit is equivalent to the centiPoise
Pascal•second; often the milliPascal•second or its equivalent
(cP), which is shown in parentheses.
the centiPoise is found more convenient.
1.6 This standard does not purport to address all of the
3.1.6.1 apparent viscosity—the viscosity of a non-
safety concerns, if any, associated with its use. It is the
Newtonian fluid at a given shear rate or shear stress determined
responsibility of the user of this standard to establish appro-
by this test method.
priate safety and health practices and to determine the
3.2 Definitions of Terms Specific to This Standard:
applicability of regulatory limitations prior to use.
3.2.1 idling oil —an oxidatively stable Newtonian oil in-
jected into the operating viscometer stator when the instrument
2. Referenced Documents
is likely to be held for periods of time greater than 30 min and
2.1 ASTM Standards:
up to two weeks at 100°C. Use of this oil prevents stator
D 4683 Test Method for Measuring Viscosity at High Shear
deposits from additives, which may decompose after longer
Rate and High Temperature by Tapered Bearing Simula-
exposure times in the operating viscometer and permits con-
tor
tinuous operation of the viscometer without need to shut the
instrument off.
3.2.2 Newtonian Reference Oil —a specially blended New-
This test method is under the jurisdiction of ASTM Committee D02 on
tonian oil that has the same viscosity at 100°C as the
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.07.0B on High Temperature Rheology of Non-Newtonian Fluids. non-Newtonian reference oil of 3.2.3.
Current edition approved Feb. 10, 2001. Published August 2001.
3.2.3 non-Newtonian reference oil —a specially formulated
Available from Tannas Co., 4800 James Savage Rd., Midland, MI 48642. This
non-Newtonian oil, identified as NNR-10, having a selected
viscometer and associated equipment as listed in the research report was used to
6 –1
apparent viscosity at 1•10 s shear rate. The oil is used to
develop the precision statement. To date, no other equipment has demonstrated,
through ASTM interlaboratory testing, the ability to meet the precision of this test.
establish an operating gap between the rotor and stator which
6 –1
This is not an endorsement or certification by ASTM.
will produce 1•10 s shear rate when the rotor height is
Annual Book of ASTM Standards, Vol 05.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6616
adjusted to give a torque output equivalent to that of the special between the spinning rotor and stationary stator. The rotor
reference oil described in 3.2.2. exhibits a reactive torque to the viscous resistance of each test
3.2.4 reciprocal torque intersection, 1/T —the rotor position oil and the value of this torque response is used to determine
i
on the micrometer defined by the intersection of two straight the apparent viscosity of the test oil at 100°C.
lines generated by the reciprocal torque method using the
5. Significance and Use
Newtonian reference oil of 3.2.2 and non-Newtonian reference
oil of 3.2.3. Reciprocal torque versus rotor height measure- 5.1 Viscosity at the shear rate and temperature of this test
ments on both oils gives straight lines whose intersection, 1/T ,
method is thought to be particularly representative of bearing
i
6 –1
establishes the desired rotor position for operation at 1•10 s conditions in large medium speed reciprocating engines as well
shear rate.
as automotive and heavy duty engines operating in this
3.2.5 reference Newtonian calibration oils —specially cho- temperature regime.
sen Newtonian oils used to determine the viscosity-torque
5.2 The importance of viscosity under these conditions has
relationship of the TBS viscometer at 100°C from which the been stressed in railroad specifications.
viscosity of an unknown oil is calculated.
6. Apparatus
3.2.6 rotor height (rotor position)—the vertical position of
the rotor relative to the stator and measured by the platform
6.1 Tapered Bearing Simulator Viscometers (TBS)—a vis-
micrometer. cometer consisting of a motor connected to a slightly tapered
3.2.6.1 stored rotor height (rotor position)—the rotor posi-
rotor that fits into a matched stator. Several models of the TBS
tion with the rotor 0.50 mm above the rubbing contact position are in use. All of these are capable of analyzing test oils at
(see 3.2.7) when the instrument is shut down.
100°C but earlier models are more limited in their upper
3.2.7 rubbing contact position—the rotor height determined
viscosity range.
when the tapered rotor is lightly brought into contact with the
6.2 Different models of the tapered bearing simulator (TBS)
similarly tapered stator.
have the following upper levels of operating viscosities at
6 –1
3.2.8 test oil—any oil for which the apparent viscosity is to
1•10 s shear rate:
be determined by this test method.
6.2.1 Model Series 400 (similar to Fig. 1)—;14 mPa•s
(cP), dual speed.
4. Summary of Test Method
6.2.2 Model Series 500 (Fig. 1)—; 16 mPa•s (cP) single
4.1 A motor drives a tapered rotor closely fitted inside a speed.
matched tapered stator. Appropriate technique establishes op- 6.2.3 Model Series 600 (Fig. 2)—;100 mPa•s (cP) (usually
6 –1
eration of the viscometer to yield 1•10 s at a temperature of liquid cooled), dual speed.
100°C at which point test oils are introduced into the gap 6.2.4 Model Series SS (SuperShear) (similar to Fig. 1)—
FIG. 1 Tapered Bearing Simulator Viscometer Model 500
D 6616
FIG. 2 High Torque Tapered Bearing Simulator Viscometer Model 600
;20 mPa•s (cP), multi-speed. former but must be modified for the latter according to
6.2.5 Model Series 2100 E (Fig. 3)—;20 mPa•s (cP) (see directions from the manufacturer.
Note 2), multi-speed.
6.6 Glass Syringe—A 50-mL glass syringe equipped with a
Luer needle lock fits the tip of the filling tube for injection of
NOTE 2—TBS Models 500, 600, and SS use a so-called bouncer to
test oil into the test cell. Smaller glass and plastic syringes can
automate unloading and reloading the load cell just before taking a torque
reading. (All automated units apply the bouncer at the appropriate point of be used if any air bubble in the fill tube caused by the exchange
operation as part of their program.) If a bouncer is not on the TBS model
of syringes is first pulled up into the next syringe to be used.
used (Model 400), the effect is generated by placing the thumb on the 2
6.7 Filter Assembly—A unit made of a filter holder and
brass weight pin and turning the turntable slightly in a clockwise direction
nominal 10-μ filter is interposed between the syringe and the
and quickly releasing the turntable. The bearingless Models 2100 E do not
filling tube to remove particles capable of damaging the
require unloading the cell since there is no turntable bearing.
rotor/stator cell.
6.3 Automated System for Calibration, Injection, and Data
6.8 Data Recording Equipment—Some form of recording
Analysis Programs—An automated program for the Tapered
the torque and temperature data produced by the tapered
Bearing Simulator, simulating the manual method has been
bearing simulator is desired in order to (1) determine torque/
used.
temperature equilibrium and (2) determine the torque with
6.4 Console—The console shown in Fig. 4 is similar in
sufficient precision to calculate viscosity to the second decimal
Models 400, 500, and 600. Consoles for Series SS and 2100 E
place. Early in the use of the TBS viscometer, a strip-chart
have provisions for changing motor speed. All consoles contain
recorder was used, later an automated, computer-based record-
the power source for the load cell, thermoregulator circuit,
ing system was developed with both a computer-simulated
stator-heating element, and motor. They also contain the
strip chart and with data digitally recorded.
circuitry for regulating and monitoring the temperature of the
oil in the stator as well as the amplifier and digital readout of
NOTE 4—Although the console has a torque indicator that can be used
for determining viscosity, it has been found that the small oscillatory
the load cell.
variation of torque with time makes desirable the recording and analysis
NOTE 3—The thermoregulator circuit of the TBS viscometers has
of the torque output more precise, particularly when determining torque
evolved as improvements have been made in the solid-state temperature
equilibrium.
controller and heater. To achieve the 5 min analysis time specified in this
6.8.1 Strip-chart Recorder:
test method requires a late model solid-state controller with automatic
reset coupled to a thermo-foil stator heater with small heat inertia or a
6.8.1.1 If a strip-chart recorder is used to record the torque
fast-responding thermoregulated liquid bath.
and temperature output signals, use the manufacturer’s direc-
6.5 Cooling Systems—Two cooling systems are available tions for calibrating and setting up the strip chart for recording
for TBS viscometer work at 100°C – forced air cooling and torque/temperature data (see Note 5). The torque reading must
liquid bath cooling. The stator housing is prepared for the be in milliVolts and the temperature in °C with a full-scale
D 6616
FIG. 3 Multi-Speed Tapered Bearing Simulator Viscometer Model 2100E
FIG. 4 Control Console for Tapered Bearing Simulator Viscometer Models 400, 500, and 600
information, it is desirable to use a two-pen, strip-chart recorder or its
chart range of 20° to 120°C.
computer equivalent since this provides a continuous torque/temperature
6.8.1.2 Use a chart speed of 1 cm/min for recording.
record of torque/temperature equilibrium necessary for precision in
6.8.1.3 Set and, when necessary, reset, the strip chart torque
calibration and in calculating viscosity.
voltage to that which will permit recording the torque as much
as possible on the upper two-thirds of the chart paper for
6.8.2 Computer Accumulation of Torque and Temperature
maximum sensitivity.
Data—Computer recording of digital data can also be used for
6.8.1.4 Factor the resulting voltage values to calculate the
the test method. Such programs should show data for both
correct values of torque.
torque and stator temperature. Torque information should be
capable of permitting the calculation of viscosity to the second
NOTE 5—Although the digital information from the torque output meter
on the viscometer console can be, and is, used for recording additional test decimal place.
D 6616
level must be kept constant.
7. Materials
9.1.2 Liquid Cooling—Connect liquid cooling bath tubing
7.1 Reference Newtonian Calibration Oils , Newtonian oils
from bath pump to the stator housing and the back of the
of known dynamic viscosity at 100°C. Table 1 shows the
console using insulated tubing according to the manufacturer’s
dynamic viscosity values of five Newtonian oils used in
directions.
developing the information for this test method.
9.2 If some days or weeks have elapsed since last use of the
7.2 Idling Oil—See 3.2.1 for information and use.
TBS viscometer, follow the manufacturer’s instructions regard-
7.3 Non-Newtonian Reference Oil , essential in setting the
6 –1
ing set-up and alignment of the rotor in the stator, checking the
rotor/stator gap to 1•10 s shear rate. The nominal level of
accuracy of the RTD and, if necessary, adjusting to 100.0°C.
apparent viscosity of non-Newtonian reference oil, NNR-10
Shut the power off and go to 9.3.
used in applying this test method is given in Table 1.
7.4 Polar Solvent, such as dimethyl sulfoxide is used to
NOTE 10—Directions for preparation of the tapered bearing simulator
dissolve any deposits on the rotor/stator surfaces after extended
viscometer and console are supplied with the equipment. One of the most
use. important directions to be followed is the alignment of the rotor and stator
before initial use of the viscometer. For those TBS Models (other than
7.5 Source of moderate pressure
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.