DIN 53019-2-2001 Viscosimetry - Measurement of viscosities and flow curves by means of rotation viscosimeters - Part 2 Viscosimeter calibration and determination of the uncertainty.pdf

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1、ICS 17.060Viskosimetrie Messung von Viskositten und Fliekurven mit Rotationsviskosimetern Teil 2: Viskosi-meterkalibrierung und Ermittlung der MessunsicherheitIn keeping with current practice in standards published by the International Organization for Standardization(ISO), a comma has been used thr

2、oughout as the decimal marker.ForewordThis standard has been prepared by Technical Committee Viskosimetrie of the NormenausschussMaterialprfung (Materials Testing Standards Committee).The DIN 53019 series of standards comprises the following:Part 1 Measurement of viscosity and flow curves using stan

3、dard design rotational viscometersPart 2 Viscometer calibration and determination of uncertainty of measurementContentsPage PageRef. No. DIN 53019-2 : 2001-02English price group 13 Sales No. 011312.01DEUTSCHE NORM February 200153019-2Continued on pages 2 to 25. No part of this translation may be rep

4、roduced without the prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ViscometryDetermination of viscosity and flow curves withrotational viscometersPart 2: Viscometer calibra

5、tion and determination ofuncertainty of measurementTranslation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Normative references . . . . . . . . . . . . .

6、. . . . . 23 Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Controlled-rate (CR) rotationalviscometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2 Controlled-stress (CS) viscometer . . . . . . . 23.3 Torque standard . . . . . . . . . . . . . . . . . . . . . . 2

7、3.4 Newtonian standard sample . . . . . . . . . . . . 24 Quantities, symbols and units . . . . . . . . . . . 25 Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Calibration of measuring system . . . . . . . . . 47 Calibration of angular velocitymeasuring system . . . . . . . .

8、. . . . . . . . . . . . . 48 Torque calibration . . . . . . . . . . . . . . . . . . . . . 58.1 Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58.2 Calibration using deflection rollers,threads and weights . . . . . . . . . . . . . . . . . . . 58.3 Calibration using a torque standar

9、d . . . . . . 78.4 Calibration using Newtonian liquids . . . . . . 89 Calibration of temperaturemeasurement . . . . . . . . . . . . . . . . . . . . . . . . . 810 Determining uncertaintyof measurement . . . . . . . . . . . . . . . . . . . . . . 810.1 Viscosity and flow curves . . . . . . . . . . . .

10、. . 810.2 Concentric-cylinder viscometers . . . . . . . . 910.2.1 Calculation of uncertaintyof measurement . . . . . . . . . . . . . . . . . . . . 910.2.2 Cylinder-face effect . . . . . . . . . . . . . . . . . 910.2.3 Checking the uncertaintyof measurement . . . . . . . . . . . . . . . . . . . 1010.

11、2.4 Indirect torque calibration . . . . . . . . . . . 1010.2.5 Relative measurement of viscosityand flow curves . . . . . . . . . . . . . . . . . . . 1010.3 Cone-and-plate viscometers . . . . . . . . . . 1010.3.1 Calculating the uncertaintyof measurement . . . . . . . . . . . . . . . . . . . 1010.3.

12、2 Spacing between cone and plate . . . . . 1110.3.3 Filling volume . . . . . . . . . . . . . . . . . . . . . 1411 Influence of application conditions . . . . . 15Appendix A Explanatory notes on uncertaintyof measurement . . . . . . . . . . . . . . 16Appendix B Explanatory notes on determiningthe unc

13、ertainty of torque measure-ment by the thread-and-rollermethod . . . . . . . . . . . . . . . . . . . . . 18Appendix C Indirect calibration of temperaturemeasuring device . . . . . . . . . . . . . 20Appendix D Examples . . . . . . . . . . . . . . . . . . . 21Page 2DIN 53019-2 : 2001-021 ScopeThis sta

14、ndard covers viscometers having concentric-cylinder and cone-and-plate geometries in the steady-state rotational mode (see clauses 2 and 3 of DIN 53018-1, March 1976 edition). It requires test signals ormeasured values for torque and angular velocity (e.g. as part of a calibration programme in the c

15、ase of computer-controlled instruments).The standard can be applied both to controlled-rate (CR) and controlled-stress (CS) viscometers and describesa method of calibrating rotational viscometers for rotational operation (as distinct from oscillation operation) andof determining contributions to the

16、 uncertainty of measurement made by the test equipment. This tracesviscometers intended for determining viscosity and flow curves back to SI basic units as represented by nationalor international (measurement) standards; thus, basic requirements are met for the inclusion of rotationalviscometers in

17、QS systems.2 Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. These normativereferences are cited at the appropriate places in the text, and the titles of the publications are listed below. Fordated references, subsequent amendments t

18、o or revisions of any of these publications apply to this standardonly when incorporated in it by amendment or revision. For undated references, the latest edition of thepublication referred to applies.DIN 1319-1 Basic concepts in metrology General conceptsDIN 1319-3 Basic concepts in metrology Eval

19、uating measurements of a single measurand and expressionof uncertaintyDIN 1342-1 Viscosity Rheological conceptsDIN 1342-2 Viscosity of Newtonian liquidsDIN 53018-1 Determining the dynamic viscosity of Newtonian liquids using rotational viscometers PrinciplesDIN 53018-2 Determination of the dynamic v

20、iscosity of Newtonian liquids using rotational viscometers Errorsources and corrections in cylinder rotational viscometersDIN 53019-1 Measurement of viscosity and flow curves using standard design rotational viscometers1 Guide to the expression of uncertainty in measurement, International Organizati

21、on for Standardization(ISO), 19932 Weise, K. and Wger, W., Comparison of two measurement results using the Bayesian theory ofmeasurement uncertainty. Meas. Sci. Technol., 1994: 5, 8798823 Bauer, H., Bse, N. and tern, P., Colloid Polym. Sci., 1995: 273, 480489.3 ConceptsIn addition to the concepts de

22、fined in DIN 1319-1, DIN 1342-1, DIN 1342-2, DIN 53018-1 and DIN 53019-1, thefollowing concepts apply.3.1 Controlled-rate (CR) rotational viscometerA viscometer with controlled rotational speed.3.2 Controlled-stress (CS) viscometerA rotational viscometer with torque control.3.3 Torque standardA mate

23、rial measure or measuring instrument for displaying the torque unit for the purpose of use in other torquemeasuring instruments.3.4 Newtonian standard sampleA sample of a Newtonian standard liquid whose viscosity has been measured at one or more temperatures usingstandard viscometers and whose visco

24、sity and its traceability to the national standard for the viscosity unit hasbeen documented and that serves as a material measure for promulgation of the unit of viscosity.4 Quantities, symbols and unitsIn addition to the quantities, symbols and units used in DIN 53019-1, the following apply.Page 3

25、DIN 53019-2 : 2001-02Table 1: Quantities, symbols and unitsSymbol(s) Quantity SI unit Other legal unita Cone angle of cone-and-plate viscometers rad (degree)rep,ggif it does, this will have to be taken into account in calculating the uncertainty of measurement(see clause 10).If the measuring system

26、includes a device for adjusting and measuring the position of the two parts of the systemrelative to each other (e.g. for adjusting the axial spacing of cone and plate), it shall be included in the calibration.Means of measurement (e.g. an alignment telescope, gauge blocks and possibly auxiliary dev

27、ices will benecessary for this purpose).Other geometrical parameters (e.g. shaft diameter, cone angle at the bottom of the inner cylinder in concentriccylinder viscometers having standard DIN 53019-1 geometry, total length of the external cylinder, etc.) shall bechecked as part of a preliminary test

28、 for compliance with the tolerances stipulated in standards or by themanufacturer.If the tolerances specified by the manufacturer for the metrologically relevant dimensions are regarded as theiruncertainties of measurement and if the resultant overall uncertainty of measurement resulting from the es

29、timateof the uncertainty of measurement is acceptable for the particular application of the viscometer, a check forcompliance with the tolerances on the dimensions may be substituted for the calibration, which should be thestandard case.NOTE: The use of gauges makes such checking simpler than measur

30、ing the relevant dimensions; theuncertainty related to such gauges should not exceed 20 % of the particular tolerance limit.7 Calibration of angular velocity measuring systemThe angular velocity of the rotating element of the measuring system shall be determined using a calibrated time/frequency and

31、 angle measuring instrument (e.g. an incremental transducer) and compared with the instrumentreading, the determination being repeated at several angular velocities in the measurement range of the system.The systematic deviation of the angular velocity from the instrument reading shall be taken as t

32、he calibrationfactor, fV, i.e.Page 5DIN 53019-2 : 2001-02V = VA fV(1)If the relationship is nonlinear, the calibration function fV(V) shall be substituted for fV.If the angular velocity indicated by the viscometer is temperature-dependent (e.g. test or ambient temperature,internal heating), the cali

33、bration shall be carried out at various temperatures. In such cases, fVwill then also bea function of temperature.It is often sufficient to determine the mean angular velocity during one revolution, no additional angularmeasuring instruments then being required. For this purpose, markings shall be m

34、ade on the rotating andstationary elements of the system and the time between two passes of the marking on the rotating elementdetermined.Another method is to mount a mirror on the rotating element (e.g. with adhesive wax) to reflect a light beam thatswitches an electronic timer on and off via an op

35、tical sensor once during each rotation.Variation in the rotation times determined may indicate fluctuations in the angular velocity possibly due, forexample, to system errors in the speed control system or to transmission errors.If the measured times are shorter than the time required for a complete

36、 revolution of the rotating element of thesystem, it will be necessary to check whether and to what extent the angular velocity fluctuates during onerevolution using an incremental transducer mounted concentrically on the rotating part and a frequencymeasuring instrument. The magnitude of the fluctu

37、ation shall be included in the uncertainty of angular velocity.The time taken for one revolution shall be determined from the time taken for several revolutions divided by theirnumber only if the measurement time covers several revolutions.NOTE: The relative uncertainty of the measurement of angular

38、 velocity is normally a function of the angularvelocity itself.8 Torque calibration8.1 PrincipleA known torque (input parameter), M, is applied to the spindle of the viscometer torque sensor without exertinga radial force and compared with the torque indicated by the viscometer, MA(output parameter)

39、. The differencebetween the input and output parameters shall be allowed for in the calibration of the shear stress as a calibrationconstant fM, i.e.M = MA fM(2)If the torque is not proportional to the reading, a calibration function fM(M) shall be substituted for fM.If the reading of the viscometer

40、 torque sensor depends on ambient temperature, the measurement temperatureor the internal heating, calibration shall be carried out as a function of temperature and the calibration factor willthen be a function of temperature.The known torque shall be traceable to national standards of length and ma

41、ss or of torque, i.e. the uncertaintyassociated with the torque standard must be known.NOTE: The relative uncertainty of the torque measurement is normally a function of the torque itself.8.2 Calibration using deflection rollers, threads and weightsOne of the various types of device that can be used

42、 to calibrate the torque measuring system of a rotationalviscometer is described below.An axially aligned cylindrical disc (3) having a known external diameter shall be mounted on the vertical spindleof the viscometer torque sensor (1). The inner cylinder of a measuring system may be used instead of

43、 a disc.It is essential to relate the diameter of the disc (or cylinder), 2 R, to the standard unit of length by measuring itwith a calibrated length meter. A mounting device (4) having two deflection rollers (5) offset in parallel by 2 Rshall be mounted in such a way with respect to the viscometer

44、support (2) that the upper tangent to the rollersis horizontal and at about half the height of the disc.Two flexible threads (6), which are to be as thin as possible, shall be placed round the disc and each of the rollersso that they are above these and parallel to one another in the plane of the ho

45、rizontal tangent at the rollers. Thesuspended parts of the threads shall be linked to one another by a bridge (7), the spacing of the attachmentpoints (8) of the threads to the bridge being such that both threads are vertical. The radius of the rollers shall beas large as possible.A weight (9) that

46、exerts a force F is suspended in the centre of the bridge, resulting in forces in the two threadsequal to 0,5 F and generating a torque, M, of:M=F (R + rF)2 MR(3)The torque sensor shall be calibrated at various points in its measurement range by changing the weight (9).NOTE: If necessary, the torque

47、 due to friction MRas a function of the bearing loading can be determined in aseparate test using threads and weights. The bearings used may be low-friction ball bearings (whosefrictional torque varies little during one revolution), air bearings or conical bearings (account being taken ofPage 6DIN 5

48、3019-2 : 2001-02the radial loading). The quiescent frictional torque can be reduced to less than 0,003 mN . m by using a wellcleaned low-noise precision ball bearing lubricated with a little oil having a viscosity of about 1,5 mPa . s.In this case, the torque sensor is calibrated in the static state

49、, i.e. the spindle of the torque sensor is stationary;consequently, in systems in which the torque of the rotating element is measured, any bearing friction duringoperation is not included.The method described has to be modified to calibrate instruments controlled by shear stress. For example, theweight, which in this case has to be somewhat larger than that required to generate the maximum torque, maybe placed on the pan of a balance, the latter being adjusted to zero by counterbalancing. Torques are then tobe applied to the viscometer that partially remov