1、September 2008DEUTSCHE NORM Normenausschuss Materialprfung (NMP) im DINDIN-SprachendienstEnglish price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of
2、 sale for German Standards (DIN-Normen).ICS 17.060!$WV:“1525123www.din.deDDIN 53019-1Viscometry Measurement of viscosities and flow curves by means of rotationalviscometers Part 1: Principles and geometry of measuring systemEnglish translation of DIN 53019-1:2008-09Viskosimetrie Messung von Viskosit
3、ten und Fliekurven mit Rotationsviskosimetern Teil 1: Grundlagen und MessgeometrieEnglische bersetzung von DIN 53019-1:2008-09Viscosit Mesurage des viscosits et des courbes dcoulement par des viscosimtres rotation Partie 1: Concepts fondamentaux et gomtrie du mesurageTraduction anglaise de DIN 53019
4、-1:2008-09SupersedesDIN 53019-1:1980-05 andDIN 53018-1:1976-03www.beuth.deDocument comprises pages2202.10 DIN 53019-1:2008-09 A comma is used as the decimal marker. Contents Page Foreword3 1 Scope 4 2 Normative references4 3 Terms and definitions .5 4 Symbols and units.6 5 Principle7 6 Apparatus .7
5、7 Sampling and sample preparation.8 8 Procedure .8 9 Flow zone patterns 9 Bibliography 22 2 DIN 53019-1:2008-09 Foreword This standard has been prepared by Working Committee NA 062-08-31 AA Viskosimetrie of the Normenausschuss Materialprfung (Materials Testing Standards Committee). DIN 53019, Viscom
6、etry Measurement of viscosities and flow curves by means of rotational viscometers comprises: Part 1: Principles and geometry of measuring system Part 2: Viscometer calibration and determination of the uncertainty of measurement Part 3: Measurement errors and corrections Amendments This standard dif
7、fers from DIN 53018-1:1976-03 and DIN 53019-1:1980-05 as follows: a) DIN 53018-1:1976-03 and DIN 53019-1:1980-05 have been combined. b) The contents have been rearranged and updated. Previous editions DIN 53788: 1974-04 DIN 53018-1: 1976-03 DIN 53019-1: 1980-05 3 DIN 53019-1:2008-09 1 Scope This sta
8、ndard specifies flow zones for measuring the flow behaviour of Newtonian and non-Newtonian fluids in rotational viscometers by describing a number of instrument geometries, the flow behaviour being described by the shear viscosity1), the shear viscosity function1), the viscosity curve1)or the flow c
9、urve1)(i.e. the graph of the relationship between shear rate and shear stress). This standard can only be applied if the following conditions are met. a) There is no slippage between the fluid and the boundary surfaces, i.e. the fluid adheres to the walls. NOTE Wall adhesion is not the same as wall
10、wetting. b) The accelerating forces in the fluid remain so low that the flow pattern is determined solely by laminar, stationary layer flow. c) Any variations in the temperature of the fluid with location and time are negligible. d) The flow zones are described by boundary surfaces, each of which co
11、mprises a lateral cylinder surface, a lateral cone surface or a circular surface (simple boundary surfaces). In practice, composite boundary surfaces are also used. e) Any boundary surfaces other than these simple ones have no effect on the flow zone. f) Any circularity defects in the boundary surfa
12、ces or errors in their axial alignment shall be negligible. Any deviations from the above conditions will increase the uncertainty of measurement (see DIN 53019-2) unless they can be compensated for by appropriate corrections (see DIN 53019-3). 2 Normative references The following referenced documen
13、ts are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the document (including any amendments) applies. DIN 1342-1, Viscosity Rheological concepts DIN 1342-2, Viscosity of Newtonian liquids DIN 13
14、42-3, Viscosity of non-Newtonian liquids DIN 53019-2, Viscometry Determination of flow curves with rotational viscometers Part 2: Viscometer calibration and determination of uncertainty of measurement DIN 53019-3, Viscometry Measurement of viscosities and flow curves by means of rotational viscomete
15、rs Part 3: Measurement errors and corrections _ 1)See DIN 1342-1. 4 DIN 53019-1:2008-09 3 Terms and definitions For the purpose of this standard, the terms and definitions given in DIN 1342-1, DIN 1342-2, DIN 1342-3 and the following apply. 3.1 measurement gap space between the boundary surfaces 3.2
16、 gap width separation between the boundary surfaces, e.g. as defined by the difference in radii, the taper angle or the plate separation NOTE For a given angular velocity, the gap geometry determines the shear rate, (see DIN 1342-1 for definition), of the fluid in the measurement gap. in this case t
17、he temperature shall be measured before and/or after shearing of the sample during viscosity or flow curve measurements since the immersion of the temperature sensor will disturb the flow zone; b) indirectly by means of temperature sensors that are incorporated in the measuring system or in the temp
18、erature-control jacket surrounding the measuring system; in this case the temperature can be measured continuously during the entire measurement. 7 DIN 53019-1:2008-09 Differences between the sample temperature and the measured temperature are to be expected, particularly if the measurement temperat
19、ure differs markedly from the ambient temperature (see DIN 53019-2). 7 Sampling and sample preparation Sampling and sample preparation procedures will depend on the requirements relating to the material concerned. The size of any solid particles in the sample shall not be greater than one fifth of t
20、he narrowest point in the measurement gap. In the case of a cone-and-plate system, this is equal to the height of the truncated cone. NOTE Solid particles may give rise to additional measurement errors in cone-and-plate systems in which the cone is not truncated. 8 Procedure Calibrate the viscometer
21、 and measurement system as specified in DIN 53019-2. Introduce the amount of sample required by the measurement system (see 9.2.4 and DIN 53019-2) ensuring it is free from bubbles and bring the apparatus and the sample to the specified measurement temperature. The procedure adopted for measuring the
22、 viscosity and flow curve will depend on the particular requirements and, especially in the case of non-Newtonian samples, on the properties of the sample under test. Thus, it may be necessary or desirable to wait for rather longer than the time taken to reach the right temperature (e.g. in the case
23、 of thixotropic samples) or to perform a preliminary shearing before starting the measurement. Depending on the type of apparatus or on the chosen mode of operating it, preset the angular velocity or the torque to a specific value and measure the resultant torque or angular velocity response signal,
24、 respectively. When measuring equilibrium values for II: Searle type) c) Plot of maximum shear rate, II: curve for Searle type based on equation (13) Figure 1 Flow zone patterns for basic flow in a cylindrical rotational viscometer 10 DIN 53019-1:2008-09 9.2.2 Description of flow zone The surfaces t
25、hat have the same angular velocity are lateral cylinder surfaces having the same radius r. The radius of the outside surface of the inner cylinder is denoted by Riand that of the inside surface of the outer cylinder by Ra. The radius ratio, , and the gap width, , are defined by equations (3) and (4)
26、 respectively: iaRR= (3) iaRR = (4) The flow zone is described by the cylindrical polar coordinates r, and z (see Figure 1). The flow zone coefficient for a finite portion of length L of a cylinder extending infinitely in the z-direction is given according to Margules by equation (5): 222i2i2a2i2a14
27、141 =RLRRRRLk(5) The correction for errors due to the finite length of the cylinders is dealt with in DIN 53019-3 (see also DIN 53019-2:2001-02, 10.2.2). 9.2.3 Description of basic flow In cylindrical rotational viscometers, surfaces having the same angular velocity are also surfaces having the same
28、 shear rate and the same shear stress. The shear rate, 3,0,1,1,3iaisiii=RRRRRLRLRL“(14)This ensures that the geometrical flow zone is similar regardless of the size of the measuring system. NOTE The numerical value of 1,084 7 for is based on the original choice of the design values: 85,02ai=RR(15) a
29、nd = 1120 (16) If these values are adopted, the amount of sample (filling volume) required will be given by: 12 DIN 53019-1:2008-09 8,17 = 3iRV (17) Key 1 Bottom of measuring vessel 2 Outer cylinder 3 Inner cylinder 4 Filling level Figure 2 Standard geometry for cylindrical rotational viscometer 9.2
30、.5 Evaluation by the representative viscosity method In rotational viscometers comprising concentric cylinders, the values of and & are not constant in the measurement gap, but decrease from the inside outwards and are dependent on the law of flow. Consequently, calculations of and are advantageousl
31、y based on representative values repand & &rep. These do not occur at the external radius Raor the internal radius Ri, but at a particular point in the measurement gap. To a good approximation, repis taken as the arithmetic mean of the shear stresses at the outer and inner cylinders for the given ge
32、ometrical ratios ( R (a twisted column at viscosities greater than 109Pas, which result in the shape of the column persisting for a long time) b) A practical parallel-plate system in which H R c) Maximum shear rate as a function of flow-zone dimensions showing the linear relationship with respect to
33、 R/H (the maximum shear rate, &max, occurs at the peripheral circumference) d) Radial variation of shear rate across the measurement gap showing that it increases linearly with distance from the axis of rotation e) Axial variation in angular velocity (angular velocity profile) across the measurement
34、 gap showing that it increases linearly with distance from the stationary plate (see equation (40) Figure 4 Flow zone patterns in a parallel-plate rotational viscometer 19 DIN 53019-1:2008-09 9.4.2 Description of flow zone The surfaces having the same angular velocity are flat circular surfaces at r
35、ight angles to the axis of rotation for which z is the same. The gap width is denoted by H. The flow zone is described using cylindrical polar co-ordinates r, and z (see Figure 4). The fluid is held in the measurement gap by interfacial forces and, in the case of relatively long twisted columns, by
36、its high viscosity as well. The flow-zone coefficient can be calculated from the plate radius, R, and the plate separation, H, using equation (37): 42RHk=(37) This equation is valid for any value of the plate separation, H, but only for Newtonian fluids. 9.4.3 Description of basic flow In parallel-p
37、late rotational viscometers, the surfaces having the same angular velocity are not surfaces having the same shear rate. On the contrary, the surfaces having the same shear rate and shear stress are lateral cylinder surfaces for which r is constant (0 r R). The shear rate, & (r), as a function of the
38、 co-ordinate r is described by equations (38) and (39): ( ) rHr =& (38) RH=max&(39) The variation in angular velocity, (z), across the measurement gap is given by equation (40): ( ) zHz = (40) z being equal to 0 at the stationary boundary surface. The angular velocity profile is shown in Figure 4 e)
39、. Although the distribution of the shear rate in the measurement gap is independent of the flow properties of the sample under investigation, this is not the case for the shear stress. For the rim of the parallel-plate system, where r = R, the shear stress, (R) is given by: ()+=)(RMRMR&Indlnd323(41)
40、 where M is in Nm, (R) is in s1, R is in m and is in Pa. &20 DIN 53019-1:2008-09 To calculate the shear stress for an unknown sample, it will therefore be necessary to make a number of measurements at different angular velocities in order to determine the gradient d lnM/d ln (R). &For Newtonian flui
41、ds, d lnM/d ln& (R) is equal to 1, so that: 32RMR)( = (42) 21 DIN 53019-1:2008-09 22 Bibliography 1 Giesekus, H. and Langer, G., Die Bestimmung der wahren Fliekurven nicht-newtonischer Flssigkeiten und plastischer Stoffe mit der Methode der reprsentativen Viskositt (Determination of the true flow cu
42、rves of non-Newtonian liquids and plastic materials using the method of representative viscosity). Rheologica Acta, 1977: 16, No 1, pp. 122. 2 Bauer, H. and Bse, N., Rheological properties of a micelle system in solution to be used as reference liquid with viscoplastic behaviour. Proc. Third European Rheology Conference (ed. D. R. Oliver). London, New York: Elsevier Applied Science, 1990, p. 37.
