ASTM D6616-07(2012)
(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
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.
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.2Note 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 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 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 (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.
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Standards Content (Sample)
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Designation: D6616 − 07 (Reapproved 2012)
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 D6616; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the laboratory determination of
6 –1
D4683 Test Method for Measuring Viscosity of New and
the viscosity of engine oils at 100°C and 1·10 s using the
Used Engine Oils at High Shear Rate and High Tempera-
Tapered Bearing Simulator (TBS) viscometer.
ture by Tapered Bearing Simulator Viscometer at 150 °C
NOTE 1—This test method is similar to Test Method D4683 which uses
D4741 Test Method for Measuring Viscosity at High Tem-
the same TBS viscometer to measure high shear viscosity at 150°C.
peratureandHighShearRatebyTapered-PlugViscometer
1.2 The Newtonian calibration oils used to establish this test
3. Terminology
method range from approximately 5 to 12 mPa·s (cP) at 100°C
and either the manual or automated protocol was used by each
3.1 Definitions:
participant in developing the precision statement.The viscosity
3.1.1 density, n—mass per unit volume. In the SI, the unit of
range of the test method at this temperature is from 1 mPa·s
density is the kilogram per cubic metre. For practical use, the
(cP) to above 25 mPa·s (cP), depending on the model of TBS.
submultiple, gram per cubic centimetre, is more convenient.
The density in gram per cubic centimetre is equal to 1/1000 the
1.3 The non-Newtonian reference oil used to establish the
6 –1 density in kg/m .
shear rate of 1·10 s for this test method has a viscosity of
3.1.2 Newtonianoilorfluid,n—anoilorfluidthatatagiven
approximately 10 mPa·s at 100°C.
temperature exhibits a constant viscosity at all shear rates or
1.4 Application to petroleum products other than engine oil
shear stresses.
has not been determined in preparing the viscometric informa-
3.1.3 non-Newtonian oil or fluid, n—an oil or fluid that
tion for this test method.
exhibits a viscosity that varies with changing shear stress or
1.5 The values stated in SI units are to be regarded as
shear rate.
standard. No other units of measurement are included in this
3.1.4 shear rate, n—the velocity gradient in fluid flow. The
–1
standard. This test method uses the milliPascal second (mPa·s)
SI unit for shear rate is s .
as the unit of viscosity.This unit is equivalent to the centiPoise
3.1.5 shear stress, n—the motivating force per unit area for
(cP), which is shown in parentheses.
fluid flow. The area is the area under shear. The SI unit for
1.6 This standard does not purport to address all of the
shear stress is the Pa.
safety concerns, if any, associated with its use. It is the
3.1.6 viscosity, n—the ratio between the applied shear stress
responsibility of the user of this standard to establish appro-
and the rate of shear. It is sometimes called the coefficient of
priate safety and health practices and to determine the
dynamic viscosity. This coefficient is a measure of the resis-
applicability of regulatory limitations prior to use.
tance to flow of the liquid. In the SI, the unit of viscosity is the
Pascal·second; often the milliPascal·second or its equivalent
the centiPoise is found more convenient.
This test method is under the jurisdiction of ASTM Committee D02 on
3.1.6.1 apparent viscosity, n—the viscosity of a non-
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Newtonianfluidatagivenshearrateorshearstressdetermined
Subcommittee D02.07 on Flow Properties.
by this test method.
Current edition approved Nov. 1, 2012. Published November 2012. Originally
approved in 2001. Last previous edition approved in 2007 as D6616–07. DOI:
10.1520/D6616-07R12.
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
throughASTM International interlaboratory testing, the ability to meet the precision Standards volume information, refer to the standard’s Document Summary page on
of this test. This is not an endorsement or certification by ASTM International. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6616 − 07 (2012)
3.2 Definitions of Terms Specific to This Standard: conditionsinlargemediumspeedreciprocatingenginesaswell
3.2.1 idling oil , n— an oxidatively stable Newtonian oil as automotive and heavy duty engines operating in this
injected into the operating viscometer stator when the instru- temperature regime.
ment is likely to be held for periods of time greater than 30 min
5.2 The importance of viscosity under these conditions has
and up to two weeks at 100°C. Use of this oil prevents stator
been stressed in railroad specifications.
deposits from additives, which may decompose after longer
exposure times in the operating viscometer and permits con-
6. Apparatus
tinuous operation of the viscometer without need to shut the
6.1 Tapered Bearing Simulator Viscometers (TBS)—a vis-
instrument off.
2 cometer consisting of a motor connected to a slightly tapered
3.2.2 Newtonian Reference Oil , n—a specially blended
rotor that fits into a matched stator. Several models of the TBS
Newtonian oil that has the same viscosity at 100°C as the
are in use. All of these are capable of analyzing test oils at
non-Newtonian reference oil of 3.2.3.
100°C but earlier models are more limited in their upper
3.2.3 non-Newtonian reference oil , n—a specially formu-
viscosity range.
lated non-Newtonian oil, identified as NNR-10, having a
6 –1
6.2 Different models of the tapered bearing simulator (TBS)
selected apparent viscosity at 1·10 s shear rate. The oil is
have the following upper levels of operating viscosities at
used to establish an operating gap between the rotor and stator
6 –1
6 –1
1·10 s shear rate:
which will produce 1·10 s shear rate when the rotor height is
6.2.1 Model Series 400 (similar to Fig. 1)—;14 mPa·s
adjustedtogiveatorqueoutputequivalenttothatofthespecial
(cP), dual speed.
reference oil described in 3.2.2.
6.2.2 Model Series 500 (Fig. 1)—; 16 mPa·s (cP) single
3.2.4 reciprocal torque intersection, 1/T ,n—the rotor
i
speed.
position on the micrometer defined by the intersection of two
6.2.3 Model Series 600 (Fig. 2)—;100 mPa·s (cP) (usually
straight lines generated by the reciprocal torque method using
liquid cooled), dual speed.
the Newtonian reference oil of 3.2.2 and non-Newtonian
6.2.4 Model Series SS (SuperShear) (similar to Fig. 1)—
reference oil of 3.2.3. Reciprocal torque versus rotor height
;20 mPa·s (cP), multi-speed.
measurements on both oils gives straight lines whose
intersection, 1/T, establishes the desired rotor position for 6.2.5 Model Series 2100 E (Fig. 3)—;20 mPa·s (cP) (see
i
6 –1
Note 2), multi-speed.
operation at 1·10 s shear rate.
3.2.5 reference Newtonian calibration oils , n—specially
NOTE 2—TBS Models 500, 600, and SS use a so-called bouncer to
chosen Newtonian oils used to determine the viscosity-torque automate unloading and reloading the load cell just before taking a torque
reading. (All automated units apply the bouncer at the appropriate point of
relationship of the TBS viscometer at 100°C from which the
operation as part of their program.) If a bouncer is not on the TBS model
viscosity of an unknown oil is calculated.
used (Model 400), the effect is generated by placing the thumb on the
3.2.6 rotor height (rotor position), n— the vertical position
brass weight pin and turning the turntable slightly in a clockwise direction
of the rotor relative to the stator and measured by the platform and quickly releasing the turntable.The bearingless Models 2100 E do not
require unloading the cell since there is no turntable bearing.
micrometer.
6.3 Automated System for Calibration, Injection, and Data
3.2.6.1 stored rotor height (rotor position), n—the rotor
Analysis Programs—An automated program for the Tapered
position with the rotor 0.50 mm above the rubbing contact
Bearing Simulator, simulating the manual method has been
position (see 3.2.7) when the instrument is shut down.
used.
3.2.7 rubbing contact position, n—the rotor height deter-
mined when the tapered rotor is lightly brought into contact
6.4 Console—The console shown in Fig. 4 is similar in
with the similarly tapered stator. Models 400, 500, and 600. Consoles for Series SS and 2100 E
haveprovisionsforchangingmotorspeed.Allconsolescontain
3.2.8 test oil, n—any oil for which the apparent viscosity is
the power source for the load cell, thermoregulator circuit,
to 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
4.1 A motor drives a tapered rotor closely fitted inside a
the load cell.
matched tapered stator. Appropriate technique establishes op-
6 –1
NOTE 3—The thermoregulator circuit of the TBS viscometers has
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
exhibits a reactive torque to the viscous resistance of each test
reset coupled to a thermo-foil stator heater with small heat inertia or a
oil and the value of this torque response is used to determine
fast-responding thermoregulated liquid bath.
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
5.1 Viscosity at the shear rate and temperature of this test former but must be modified for the latter according to
method is thought to be particularly representative of bearing directions from the manufacturer.
D6616 − 07 (2012)
FIG. 1 Tapered Bearing Simulator Viscometer Model 500
FIG. 2 High Torque Tapered Bearing Simulator Viscometer Model 600
6.6 Glass Syringe—A50-mLglass syringe equipped with a be used if any air bubble in the fill tube caused by the exchange
Luer needle lock fits the tip of the filling tube for injection of
of syringes is first pulled up into the next syringe to be used.
test oil into the test cell. Smaller glass and plastic syringes can
D6616 − 07 (2012)
FIG. 3 Multi-Speed Tapered Bearing Simulator Viscometer Model 2100E
FIG. 4 Control Console for Tapered Bearing Simulator Viscometer Models 400, 500, and 600
6.7 Filter Assembly— A unit made of a filter holder and place. Early in the use of the TBS viscometer, a strip-chart
nominal 10-µ filter is interposed between the syringe and the
recorder was used, later an automated, computer-based record-
filling tube to remove particles capable of damaging the
ing system was developed with both a computer-simulated
rotor/stator cell.
strip chart and with data digitally recorded.
6.8 Data Recording Equipment—Some form of recording
NOTE 4—Although the console has a torque indicator that can be used
the torque and temperature data produced by the tapered
for determining viscosity, it has been found that the small oscillatory
bearing simulator is desired in order to (1) determine torque/
variation of torque with time makes desirable the recording and analysis
temperature equilibrium and (2) determine the torque with
of the torque output more precise, particularly when determining torque
equilibrium.
sufficient precision to calculate viscosity to the second decimal
D6616 − 07 (2012)
6.8.1 Strip-chart Recorder: 8. Sampling
6.8.1.1 If a strip-chart recorder is used to record the torque
8.1 Fifty millilitres of a representative sample of fresh or
and temperature output signals, use the manufacturer’s direc-
used test oil is placed in a 50 mL syringe equipped with
tions for calibrating and setting up the strip chart for recording
attached filter holder and 10-µ filter disk in preparation for
torque/temperature data (see Note 5). The torque reading must
injection into the TBS viscometer.
be in milliVolts and the temperature in °C with a full-scale
chart range of 20° to 120°C.
NOTE 7—It is important to always use a filter and filter disk to prevent
larger particles from entering the rotor-stator gap. However, it is also
6.8.1.2 Use a chart speed of 1 cm/min for recording.
important to note that the TBS viscometer will work with heavily particle
6.8.1.3 Set and, when necessary, reset, the strip chart torque
laden used oils as long as they are passed through the 10-µ filter.
voltage to that which will permit recording the torque as much
as possible on the upper two-thirds of the chart paper for
9. Preparation of Apparatus
maximum sensitivity.
6.8.1.4 Factor the resulting voltage values to calculate the 9.1 Set up stator cooling method, air or liquid, according to
correct values of torque. the manufacturer’s directions.
NOTE 5—Although the digital information from the torque output meter
NOTE 8—When analyzing relatively viscous oils, stator cooling is
on the viscometer console can be, and is, used for recording additional test
necessary. This is particularly the case at lower operating temperatures
information, it is desirable to use a two-pen, strip-chart recorder or its
such as 100°C where simple radiation from the stator through the stator
computer equivalent since this provides a continuous torque/temperature
housing is not sufficient to carry away the heat generated by viscous
record of torque/temperature equilibrium necessary for precision in
resistance to shear.
calibration and in calculating viscosity.
9.1.1 Air Cooling— Connect cooling air tubing to the ports
6.8.2 Computer Accumulation of Torque and Temperature
on the stator housing and the back of the console following
Data—Comput
...
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