1、Designation: E2975 161Standard Test Method forCalibration or Calibration Verification of Concentric CylinderRotational Viscometers1This standard is issued under the fixed designation E2975; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEResearch report information was editorially added to 15.4 in May 2017.INTRODUCTIONRotational viscometers h
3、ave been commonly used for viscosity measurements since the first decadeof the twentieth century. After more than one hundred years, there have been many ease-of-use,instrumentation, and data analysis improvements in these instruments. The initial constant torqueapparatus gave way to the more popula
4、r constant speed apparatus. Spindles became available suppliedwith calibration constants. Computerization led to factory calibration and automatic viscositycalculation. Even with these improvements, however, apparatus of the very earliest design is stillcommonly used throughout the world. This stand
5、ard seeks to provide users with the ability to calibrateor verify calibration of rotational viscosity apparatus in their own laboratory.1. Scope*1.1 This test method describes the calibration or calibrationverification of rotational viscometers in which the rotationalelement is immersed in a Newtoni
6、an reference material underambient temperature conditions. The method is applicable torotational-type viscometers where a constant rotational speedresults in a measured torque generated by the test specimen,and to Stormer viscometers where a constant applied torqueresults in a measured rotational sp
7、eed. It is not intended forcone-and-plate or parallel plate viscometers.1.2 Calibration shall be performed with Newtonian refer-ence materials using experimental conditions such astemperature, viscosity range, and shear rate (rotational speed),as close as practical to those to be used for measuremen
8、t of testspecimens.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions that are provided for information only and are notconsidered standard.1.3.1 Common viscosity units of Poise (P) are related to theSI units by the equivalenc
9、y 1 cP = 1 mPas.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use
10、.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers t
11、o Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE1142 Terminology Relating to Thermophysical PropertiesE1970 Practice for Statistical Treatment of ThermoanalyticalData3. Terminology3.1 DefinitionsSpecific technical terms u
12、sed in this testmethod are described in Terminologies E473 and E1142including Newtonian, non-Newtonian, stress, strain,viscometer, viscometry, and viscosity.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.08
13、 on Rheol-ogy.Current edition approved Dec. 1, 2016. Published January 2017. Originallyapproved in 2014. Last previous edition approved in 2015 as E2975 15. DOI:10.1520/E2975-16E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or
14、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesTh
15、is international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (
16、TBT) Committee.13.2 Definitions of Terms Specific to This Standard:3.2.1 viscometer, Stormer, na rotational viscometer wherea constant torque is applied to a spindle and a resultantrotational speed is measured.4. Summary of Test Method4.1 Acylindrical spindle is rotated in a Newtonian referencefluid
17、 contained in a mating cylindrical container at a known (ormeasured) speed at a defined temperature. The viscous dragexperienced by the immersed element is measured (or known)as torque. Viscosity is proportional to the torque and inverselyproportional to the shear rate (see Eq 1). A number of proxie
18、sexist for torque and shear rate. For torque, proxies include, butare not limited to, mass (accelerated by gravity operatingthrough a moment arm), and the percent extension of aspring-provided force. For shear rate, proxies include rotationalspeed in a variety of units including r/min and rad/s, tim
19、e (fora constant number of revolutions), or number of revolutions(per constant time). A proportionality constant provides for thedimensions of the spindle and unit conversion (such as r/min torad/s) factors (see Eq 2). 5 (1) 5 E (2)where: = viscosity (Pas), = rotational speed (r/min),E = calibration
20、 coefficient, = torque (Nm), and = shear rate, S1.NOTE 11 Pa = 1 N/m2; 1 cP = 1 mPas; 1 r/min = 0.1047 rad/s.4.2 The dimensions of the calibration constant depend uponthe units in which torque (or its proxy) and rotational speed (orits proxy) are observed.4.3 Modern apparatus with onboard computers
21、often pro-duce the desired measured viscosity directly. In this case, onlycalibration verification is needed to ensure a properly operatingapparatus.4.4 Calibration or calibration verification of a viscometerand its associated spindle is achieved by comparing theviscosity indicated by the apparatus
22、with that of the knownviscosity of a calibration fluid as their quotient using Eq 3,under experimental conditions used in measuring an unknownfluid:C 5 t o(3)where:t= the viscosity of the calibration fluid (Pas),o= the viscosity indicated by the apparatus (Pas), andC = calibration verification facto
23、r (dimensionless).5. Significance and Use5.1 This test method may be used to calibrate or verifycalibration of a rotational viscometer with coaxial spindlegeometries.6. Apparatus6.1 Viscometer, Concentric Cylinder RotationalThe es-sential instrumentation required providing the minimum rota-tional vi
24、scometer analytical capabilities for this test methodinclude:6.1.1 A drive motor, to apply a rotational displacement tothe specimen at a rate from 0.5 r min to 60 r/min constant to60.2 % of full scale or alternatively a torque to the specimenat a rate from 100 r min to 200 r min constant to 60.2%off
25、ull scale.6.1.2 A coupling shaft, or other means to transmit therotational displacement from the motor to the specimen.NOTE 2It is convenient to have a mark on the shaft to indicate thefluid level of the test specimen appropriate for the measurement.6.1.3 A cylindrical rotational element, spindle, b
26、ob, or tool,composed of material inert to the material being tested, to fixthe specimen between the drive shaft and a stationary position.NOTE 3Each spindle typically covers about two decades of viscosity.The spindle is selected so that the measured viscosity is between 10 % and100 % of the torque r
27、ange for that spindle.NOTE 4This test method is intended for spindles that are immersed inNewtonian viscosity reference fluids contained in a mating cylindricalcontainer. It is not intended for cone-and-plate or parallel plate viscom-eters.6.1.4 A sensor to measure the torque within 61 % of fullscal
28、e developed by the specimen or alternatively to measurerotational speed within 61 % of full scale.NOTE 5For Stormer viscometers, this sensor is sometimes a rotationalturns-counter and a timer.6.1.5 A temperature sensor to provide an indication of thespecimen temperature of the range of 19C to 26C to
29、 within60.1C.6.1.6 A temperature bath to provide a controlled isothermaltemperature environment for the specimen within the appli-cable temperature range of this test method.6.1.7 A temperature controller, capable of maintaining thebath at a temperature constant to 60.1C over the range of19C to 26C.
30、6.1.8 A data collection device, to provide a means ofacquiring, storing, and displaying measured or calculatedsignals, or both. The minimum output signals required forrotational viscosity are a signal proportional to torque, a signalproportional to shear rate such as rotational speed, temperature,an
31、d time.NOTE 6Manual recording of measured variables is permitted.6.1.9 A stand, to support, level, lower and raise the drivemotor, shaft and spindle.6.1.10 A specimen container, cylindrical in shape suitablefor the spindle (6.1.3), to contain the test specimen duringtesting.NOTE 7The specific contai
32、ner may depend upon the spindle beingused (see vendors recommendation). In the absence of other information,a low-form Griffin beaker of 600-mL capacity shall be used.6.1.11 Auxiliary instrumentation considered necessary oruseful in conducting this test method includes:E2975 16126.1.11.1 Data analys
33、is capability to provide viscosity,stress, or other useful quantities derived from measured sig-nals.6.1.11.2 A level to indicate the vertical plumb of the drivemotor, shaft, and spindle.NOTE 8Viscometers and their spindles are precision equipment andshall be kept from undue shock and mishandling. P
34、hysical damage to theinstrument may reveal itself as erratic torque or rotational speed indicationwhen the instrument, with or without a spindle in place, is operated in air.When operating normally, the indicated signal will be stable and have avalue of zero when operated in air.NOTE 9Care shall be
35、taken in the storage and handling of spindles andassemblies. Protect them from dust, corrosive deposits, and mechanicalabuse. Avoid touching the calibrated section of the spindles with thehands. Clean the spindle and sample container thoroughly after each use.7. Reagents and Materials7.1 One or more
36、 viscosity reference fluid (with its accom-panying certification) in the range of that anticipated for thetest specimen measurement.NOTE 10Viscosity reference materials are typically available from theviscometer supplier.8. Preparation of Apparatus8.1 Perform any viscometer preparation or calibratio
37、n pro-cedures described by the manufacturer in the operationsmanual.8.2 Operate the viscometer in air with a connected spindlein place. The indicator shall be stable and indicate a zero value.8.3 Set the temperature bath to 23C and equilibrate for30 min. Measure the temperature bath and ensure that
38、itstemperature is 23 6 0.2C.NOTE 11Other temperatures may be used but shall be reported.9. Procedure Preparation9.1 Selection of the Spindle:9.1.1 From the estimated viscosity of the test specimen,select a spindle that will produce readings in the desired range.NOTE 12Where more than one spindle is
39、available for the rangeselected, choose a spindle that produces results nearest the midpoint of themeasurable viscosity (or torque or rotational speed) range.9.2 Preparation of the Viscosity Reference Material:9.2.1 Place the required amount of the reference materialmeasured in the sample container.
40、NOTE 13Pour the reference material slowly down the side of thesample container, taking care to prevent incorporation of air into thematerial.NOTE 14The amount of viscosity reference material varies with eachspindle and container combination. See the manufacturers instructionmanual for the correct am
41、ount of liquid for each spindle/container pair.9.2.2 Place the container with its reference material in thetemperature bath at 23.0 6 0.2C and equilibrate for 30 min(see Note 11).9.2.3 Record the viscosity of the calibration material fromits certificate at the test temperature T as t.9.3 Assemble th
42、e Apparatus:9.3.1 Vertically align and level the viscometer on its sup-porting stand.9.3.2 Connect the spindle selected in 9.1.1 to the couplinglink.9.3.3 Align the spindle (and apparatus) over the samplecontainer.9.4 Spindle Insertion:9.4.1 Slowly lower the spindle into the reference materialcontai
43、ner until the fluid covers the spindle and reaches a levelapproximately 3 mm above the spindle active area.NOTE 15The shaft may have a mark to indicate the appropriate fluidlevel for measurement.NOTE 16Take care not to trap any air bubbles under the spindle.9.4.2 Initiate the rotation of the spindle
44、 at the lowest speedavailable for 30 min.9.4.3 Measure the temperature of the test specimen (T).NOTE 17If the temperature is not 23.0 6 0.2C, allow the testspecimen to equilibrate for an addition 30 min or until the desiredtemperature range and stability are observed.10. Method A Procedure For Appar
45、atus ReportingViscosity at Constant Speed10.1 Turn on the motor and rotate the spindle at its lowestspeed.10.2 Increase the rotational speed to that required to pro-duce a reading nearest the midpoint of the torque scale.10.3 Stop the spindle rotation and wait for 1 min.10.4 Restart the spindle rota
46、tion at the same rotational speedand allow at least five revolutions of the spindle.10.5 Measure the observed viscosity (o(1) and rotationalspeed (1).10.6 Repeat steps 10.3 10.5 two more times measuring theindicated viscosity as o(2) and o(3), respectively.10.7 Calculate the mean viscosity value fro
47、m steps 10.5 and10.6 and report as o(see Practice E1970).10.8 Using the values from 9.2.3 and 10.7, calculate thecalibration verification factor (C) using Eq 4.NOTE 18Calibration verification factors outside of the range of 0.95to 1.05 may indicate that the apparatus needs service.11. Method B Proce
48、dure For Apparatus ReportingTorque Proxy or Shear Rate Proxies11.1 Turn on the motor and rotate the spindle at its lowestspeed.11.2 Increase the torque to that required to produce arotational speed near mid-scale for the range of 100 to 200r/min.11.3 Stop the spindle and wait for 1 min.11.4 Restart
49、the spindle rotation at the same torque andallow at least five spindle rotations.11.5 Measure and record the rotational speed proxy as o(1)and the corresponding torque proxy as o(1).11.6 Repeat steps 11.3 11.5 two more times measuring therotational speed proxies o(2) and o(3) and torque proxies aso(2) and o(3).E2975 161311.7 Calculate the mean rotational speed proxy and torqueproxies from steps 11.5 and 11.6 and report as oand o(seePractice E1970).11.8 Determine the calibration coefficien
