ASTM D6616-01a(2006)
(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
SIGNIFICANCE AND USE
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.
The importance of viscosity under these conditions has been stressed in railroad specifications.
SCOPE
1.1 This test method covers the laboratory determination of the viscosity of engine oils at 100C and 1106s -1 using the Tapered Bearing Simulator (TBS) viscometer.This test method is similar to Test Method D 4683 which uses the same TBS viscometer to measure high shear viscosity at 150C.
1.2 The Newtonian calibration oils used to establish this test method range from approximately 5 to 12 mPas (cP) at 100C 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 mPas (cP) to above 25 mPas (cP), depending on the model of TBS.
1.3 The non-Newtonian reference oil used to establish the shear rate of 1106s-1 for this test method has a viscosity of approximately 10 mPas at 100C.
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 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. This test method uses the milliPascal second (mPas) as the unit of viscosity. This unit is equivalent to the centiPoise (cP), which is shown in parentheses.
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.
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Standards Content (Sample)
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An American National Standard
Designation: D 6616 – 01a (Reapproved 2006)
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 2. Referenced Documents
1.1 This test method covers the laboratory determination of 2.1 ASTM Standards:
6 –1
the viscosity of engine oils at 100°C and 1·10 s using the D 4683 Test Method for Measuring Viscosity at High Shear
Tapered Bearing Simulator (TBS) viscometer. Rate and High Temperature by Tapered Bearing Simulator
NOTE 1—This test method is similar toTest Method D 4683 which uses
3. Terminology
the same TBS viscometer to measure high shear viscosity at 150°C.
3.1 Definitions:
1.2 The Newtonian calibration oils used to establish this test
3.1.1 density—the mass per unit volume. In the SI, the unit
method range from approximately 5 to 12 mPa·s (cP) at 100°C
ofdensityisthekilogrampercubicmetre,butforpracticaluse,
and either the manual or automated protocol was used by each
a submultiple is more convenient. The gram per cubic centi-
participantindevelopingtheprecisionstatement.Theviscosity 3 3
metre is equivalent to 10 kg/m and is customarily used.
range of the test method at this temperature is from 1 mPa·s
3.1.2 Newtonian oil or fluid—an oil or fluid that at a given
(cP) to above 25 mPa·s (cP), depending on the model of TBS.
temperature exhibits a constant viscosity at all shear rates or
1.3 The non-Newtonian reference oil used to establish the
shear stresses.
6 –1
shear rate of 1·10 s for this test method has a viscosity of
3.1.3 non-Newtonian oil or fluid—an oil or fluid that exhib-
approximately 10 mPa·s at 100°C.
its a viscosity that varies with changing shear stress or shear
1.4 Application to petroleum products other than engine oil
rate.
has not been determined in preparing the viscometric informa-
3.1.4 shear rate—the velocity gradient in fluid flow. The SI
tion for this test method. –1
unit for shear rate is s .
1.5 The values stated in SI units are to be regarded as
3.1.5 shear stress—the motivating force per unit area for
standard. No other units of measurement are included in this
fluid flow. The area is the area under shear.
standard. This test method uses the milliPascal second (mPa·s)
3.1.6 viscosity—the ratio between the applied shear stress
as the unit of viscosity.This unit is equivalent to the centiPoise
and the rate of shear. It is sometimes called the coefficient of
(cP), which is shown in parentheses.
dynamic viscosity. This coefficient is a measure of the resis-
1.6 This standard does not purport to address all of the
tance to flow of the liquid. In the SI, the unit of viscosity is the
safety concerns, if any, associated with its use. It is the
Pascal·second; often the milliPascal·second or its equivalent
responsibility of the user of this standard to establish appro-
the centiPoise is found more convenient.
priate safety and health practices and to determine the
3.1.6.1 apparent viscosity—the viscosity of a non-
applicability of regulatory limitations prior to use.
Newtonianfluidatagivenshearrateorshearstressdetermined
by this test method.
3.2 Definitions of Terms Specific to This Standard:
This test method is under the jurisdiction of ASTM Committee D02 on 2
3.2.1 idling oil —an oxidatively stable Newtonian oil in-
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
jected into the operating viscometer stator when the instrument
D02.07.0B on High Temperature Rheology of Non-Newtonian Fluids.
Current edition approved May 1, 2006. Published June 2006. Originally is likely to be held for periods of time greater than 30 min and
approved in 2001. Last previous edition approved in 2001 as D 6616 – 01a.
Available from Tannas Co., 4800 James Savage Rd., Midland, MI 48642. This
viscometer and associated equipment as listed in the research report was used to For referenced ASTM standards, visit the ASTM website, www.astm.org, or
develop the precision statement. To date, no other equipment has demonstrated, contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
through ASTM interlaboratory testing, the ability to meet the precision of this test. Standards volume information, refer to the standard’s Document Summary page on
This is not an endorsement or certification by ASTM. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6616 – 01a (2006)
up to two weeks at 100°C. Use of this oil prevents stator 6. Apparatus
deposits from additives, which may decompose after longer
6.1 Tapered Bearing Simulator Viscometers (TBS)—a vis-
exposure times in the operating viscometer and permits con-
cometer consisting of a motor connected to a slightly tapered
tinuous operation of the viscometer without need to shut the
rotor that fits into a matched stator. Several models of the TBS
instrument off.
are in use. All of these are capable of analyzing test oils at
3.2.2 Newtonian Reference Oil —a specially blended New-
100°C but earlier models are more limited in their upper
tonian oil that has the same viscosity at 100°C as the
viscosity range.
non-Newtonian reference oil of 3.2.3.
6.2 Different models of the tapered bearing simulator (TBS)
3.2.3 non-Newtonian reference oil —a specially formulated
have the following upper levels of operating viscosities at
non-Newtonian oil, identified as NNR-10, having a selected
6 –1
1·10 s shear rate:
6 –1
apparent viscosity at 1·10 s shear rate. The oil is used to
6.2.1 Model Series 400 (similar to Fig. 1)—;14 mPa·s
establish an operating gap between the rotor and stator which
6 –1
(cP), dual speed.
will produce 1·10 s shear rate when the rotor height is
6.2.2 Model Series 500 (Fig. 1)—; 16 mPa·s (cP) single
adjustedtogiveatorqueoutputequivalenttothatofthespecial
speed.
reference oil described in 3.2.2.
6.2.3 Model Series 600 (Fig. 2)—;100 mPa·s (cP) (usually
3.2.4 reciprocal torque intersection, 1/T—the rotor position
i
liquid cooled), dual speed.
on the micrometer defined by the intersection of two straight
lines generated by the reciprocal torque method using the
6.2.4 Model Series SS (SuperShear) (similar to Fig. 1)—
Newtonian reference oil of 3.2.2 and non-Newtonian reference
;20 mPa·s (cP), multi-speed.
oil of 3.2.3. Reciprocal torque versus rotor height measure-
6.2.5 Model Series 2100 E (Fig. 3)—;20 mPa·s (cP) (see
ments on both oils gives straight lines whose intersection, 1/T,
i
Note 2), multi-speed.
6 –1
establishes the desired rotor position for operation at 1·10 s
NOTE 2—TBS Models 500, 600, and SS use a so-called bouncer to
shear rate.
2 automate unloading and reloading the load cell just before taking a torque
3.2.5 reference Newtonian calibration oils —specially cho-
reading. (All automated units apply the bouncer at the appropriate point of
sen Newtonian oils used to determine the viscosity-torque
operation as part of their program.) If a bouncer is not on the TBS model
relationship of the TBS viscometer at 100°C from which the
used (Model 400), the effect is generated by placing the thumb on the
viscosity of an unknown oil is calculated.
brass weight pin and turning the turntable slightly in a clockwise direction
and quickly releasing the turntable.The bearingless Models 2100 E do not
3.2.6 rotor height (rotor position)—the vertical position of
require unloading the cell since there is no turntable bearing.
the rotor relative to the stator and measured by the platform
micrometer.
6.3 Automated System for Calibration, Injection, and Data
3.2.6.1 stored rotor height (rotor position)—the rotor posi-
Analysis Programs—An automated program for the Tapered
tion with the rotor 0.50 mm above the rubbing contact position
Bearing Simulator, simulating the manual method has been
(see 3.2.7) when the instrument is shut down.
used.
3.2.7 rubbing contact position—the rotor height determined
6.4 Console—The console shown in Fig. 4 is similar in
when the tapered rotor is lightly brought into contact with the
Models 400, 500, and 600. Consoles for Series SS and 2100 E
similarly tapered stator.
haveprovisionsforchangingmotorspeed.Allconsolescontain
3.2.8 test oil—any oil for which the apparent viscosity is to
the power source for the load cell, thermoregulator circuit,
be determined by this test method.
stator-heating element, and motor. They also contain the
circuitry for regulating and monitoring the temperature of the
4. Summary of Test Method
oil in the stator as well as the amplifier and digital readout of
the load cell.
4.1 A motor drives a tapered rotor closely fitted inside a
matched tapered stator. Appropriate technique establishes op-
NOTE 3—The thermoregulator circuit of the TBS viscometers has
6 –1
eration of the viscometer to yield 1·10 s at a temperature of
evolved as improvements have been made in the solid-state temperature
100°C at which point test oils are introduced into the gap
controller and heater. To achieve the 5 min analysis time specified in this
between the spinning rotor and stationary stator. The rotor
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
exhibits a reactive torque to the viscous resistance of each test
fast-responding thermoregulated liquid bath.
oil and the value of this torque response is used to determine
the apparent viscosity of the test oil at 100°C.
6.5 Cooling Systems—Two cooling systems are available
for TBS viscometer work at 100°C: forced air cooling and
5. Significance and Use
liquid bath cooling. The stator housing is prepared for the
former but must be modified for the latter according to
5.1 Viscosity at the shear rate and temperature of this test
method is thought to be particularly representative of bearing directions from the manufacturer.
conditionsinlargemediumspeedreciprocatingenginesaswell
6.6 Glass Syringe—A50-mL glass syringe equipped with a
as automotive and heavy duty engines operating in this
Luer needle lock fits the tip of the filling tube for injection of
temperature regime.
test oil into the test cell. Smaller glass and plastic syringes can
5.2 The importance of viscosity under these conditions has beusedifanyairbubbleinthefilltubecausedbytheexchange
been stressed in railroad specifications. of syringes is first pulled up into the next syringe to be used.
D 6616 – 01a (2006)
FIG. 1 Tapered Bearing Simulator Viscometer Model 500
FIG. 2 High Torque Tapered Bearing Simulator Viscometer Model 600
6.7 Filter Assembly—A unit made of a filter holder and 6.8 Data Recording Equipment—Some form of recording
nominal 10-µ filter is interposed between the syringe and the the torque and temperature data produced by the tapered
filling tube to remove particles capable of damaging the bearing simulator is desired in order to (1) determine torque/
rotor/stator cell. temperature equilibrium and (2) determine the torque with
D 6616 – 01a (2006)
FIG. 3 Multi-Speed Tapered Bearing Simulator Viscometer Model 2100E
FIG. 4 Control Console for Tapered Bearing Simulator Viscometer Models 400, 500, and 600
variation of torque with time makes desirable the recording and analysis
sufficient precision to calculate viscosity to the second decimal
of the torque output more precise, particularly when determining torque
place. Early in the use of the TBS viscometer, a strip-chart
equilibrium.
recorder was used, later an automated, computer-based record-
ing system was developed with both a computer-simulated
6.8.1 Strip-chart Recorder:
strip chart and with data digitally recorded.
6.8.1.1 If a strip-chart recorder is used to record the torque
and temperature output signals, use the manufacturer’s direc-
NOTE 4—Although the console has a torque indicator that can be used
for determining viscosity, it has been found that the small oscillatory tions for calibrating and setting up the strip chart for recording
D 6616 – 01a (2006)
NOTE 7—It is important to always use a filter and filter disk to prevent
torque/temperature data (see Note 5). The torque reading must
larger particles from entering the rotor-stator gap. However, it is also
be in milliVolts and the temperature in °C with a full-scale
important to note that the TBS viscometer will work with heavily particle
chart range of 20° to 120°C.
laden used oils as long as they are passed through the 10-µ filter.
6.8.1.2 Use a chart speed of 1 cm/min for recording.
6.8.1.3 Set and, when necessary, reset, the strip chart torque
9. Preparation of Apparatus
voltage to that which will permit recording the torque as much
9.1 Set up stator cooling method, air or liquid, according to
as possible on the upper two-thirds of the chart paper for
the manufacturer’s directions.
maximum sensitivity.
NOTE 8—When analyzing relatively viscous oils, stator cooling is
6.8.1.4 Factor the resulting voltage values to calculate the
necessary. This is particularly the case at lower operating temperatures
correct values of torque.
such as 100°C where simple radiation from the stator through the stator
NOTE 5—Althoughthedigitalinformationfromthetorqueoutputmeter
housing is not sufficient to carry away the heat generated by viscous
on the viscometer console can be, and is, used for recording additional test
resistance to shear.
information, it is desirable to use a two-pen, strip-chart recorder or its
9.1.1 Air Cooling—Connect cooling air tubing to the ports
computer equivalent since this provides a continuous torque/temperature
on the stator housing and the back of the console following
record of torque/temperature equilibrium necessary for precision in
directions given by the manufacturer in the Owner’s Manual.
calibration and in calculating viscosity.
This will permit use of the flow meter on the left side of the
6.8.2 Computer Accumulation of Torque and Temperature
console to adjust the cooling-air flow rate.
Data—Computer recording of digital data can also be used for
9.1.1.1 Set the airflow rate at 100 SCFH.
the test method. Such programs should show data for both
torque and stator temperature. Torque information should be NOTE 9—Once airflow rate has been set, it is important that this level
bemaintainedthroughoutcalibrationandoperation.Ifdesired,theai
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