1、Viscometry Determination of kinematic viscosity using the Ubbelohde viscometer Part 1 : Apparatus and measurement procedure ICs 17.060 Descriptors: Viscometry, Ubbelohde viscometer, apparatus. DIN 51 562-1 Supersedes January 1983 edition. Viskosimetrie - Messung der kinematischen Viskositt mit dem U
2、bbelohde-Viskosimeter - Teil 1 : Bauform und Durchfhrung der Messung In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Dimensions in mm Foreword This standard has been prepared
3、by Technical Committee Viskosimetrie of the Normenausschu Material- prfung (Materials Testing Standards Committee). It should be used together with DIN 53012 and The DIN 51562 series of standards comprises the following: Part 1 Part 2 Micro-Ubbelohde viscometers Part 3 Part 4 DIN 51562-4. Apparatus
4、and measurement procedure Relative change in viscosity at short flow times Calibration of viscometers and determination of uncertainty of measurement Amendments This standard differs from the January 1983 edition as follows: a) Calibration details have been included. b) Requirements for automatic me
5、asuring equipment are now included. c) Information on the uncertainty of measurement has been included. d) An additional viscometer size (no. V) has been included. e) Details relating to the apparatus and test procedure have been changed. Previo us edit ions Supplement 1 to DIN 53655: 1947-1 2; DIN
6、51 562: 1955-04, 1964-1 O, 1967-03, 1976-02; DIN 51 562-1 : 1978-1 2, 1983-01. 1 Scope and field of application This standard specifies the design and use of Ubbelohde suspended level viscometers with ring measuring marks that indicate the flow volume. Such viscometers are used to determine the kine
7、matic viscosity of Newtonian liquids that are sufficiently transparent to enable the meniscus of the liquid to be observed during measurement. NOTE: Special automatic measuring devices also allow viscosity measurements of opaque liquids (cf. DIN 51366). Continued on pages 2 to 1 O. Translation by DI
8、N-Sprachendienst. In case of doubt, the German-language original should be consulted as the authoritative text Q No pari of this translation may be reproduced without the prior permission of Beuth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). Ref. No
9、. DIN 51562-1 : 1999-01 Sales No. 0108 11.99 DIN Deutsches Institut fur Normung e. V., Berlin. English price group 08 COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 2 DIN 51562-1 : 1999-01 2 Normative references This standard incorporates, by
10、dated or undated reference, provisions from other publications. These norma- tive references are cited at the appropriate places in the text, and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this st
11、andard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. DIN 1319-1 Basic concepts in metrology - General concepts DIN 1319-3 Basic concepts in metrology - Evaluating measurements of a single measurand and expres
12、- sion of uncertainty DIN 1342-1 Viscosity - Rheological concepts DIN 51366 Determination of kinematic viscosity of petroleum products using the Cannon-Fenske viscometer for opaque liquids DIN 51562-3 Determination of kinematic viscosity using the Ubbelohde viscometer - Relative change in viscosity
13、at short flow times DIN 51562-4 Determination of kinematic viscosity using the Ubbelohde viscometer - Calibration of viscometers and determination of uncertainty of measurement DIN 53012 Capillary viscometry of Newtonian liquids - Sources of error and corrections DIN 53017 Determination of temperatu
14、re coefficient of viscosity of liquids IS0 31 05 : 1994 Glass capillary kinematic viscometers - Specifications and operating instructions IS0 3585 : 1991 Borosilicate glass 3.3 - Properties ASTM D 21 62-79 Standard method of basic calibration of master viscometers and viscosity oil standards 3 Conce
15、pts The following concepts apply, in addition to those defined in DIN 1319-1 and DIN 1342-1. 3.1 Viscosity standard A material measure or measuring device which represents the viscosity unit (e.g. when calibrating a viscometer). 3.2 Standard viscometer For the purposes of this standard, an Ubbelohde
16、 capillary viscometer that is traceable to the national viscosity standard. NOTE: See subclause 8.1 for a description of the Ubbelohde viscometer. 3.3 Standard Newtonian liquid A Newtonian liquid whose change in viscosity with time is sufficiently small so that it is suitable as a viscosity standard
17、. 3.4 Standard viscosity sample A sample of a standard Newtonian liquid whose viscosity has been measured and recorded at one or more temperatures using standard viscometers; the traceability of the viscosity values thus obtained to the national viscosity standard shall have been documented. This sa
18、mple can thus be used as a material measure. 4 Symbols and units See tables 1 and 2 for symbols and units used in this standard. For the purposes of this standard, the Reynolds number, Re, is given by (1): Re = 637. Note that equation (1) only applies when the units given in column 4 of table 1 are
19、used. The following equations apply to the shear stress and shear rate, respectively: V R*K*t2 4.v Yw =- z.t.R3 COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 3 DIN 51562-1 : 1999-01 Shear rate at the internal wall of capillary Acceleration du
20、e to gravity at the point of measurement (for Newtonian liquids) 5 Measuring range This method is suitable for measuring kinematic viscosities within a range of 0,35 to 1 O0 O00 mm2/s (see ta- ble 2), with flow times ranging from 200 s to l O00 s at temperatures from l O “C to l O0 “C. When using th
21、e viscometer at temperatures or flow times outside the above ranges, additional errors of measurement may occur which are not included in the uncertainty of measurement specified in clause 14. 6 Principle The viscosity of the test liquid is determined by measuring the time it takes for the sample, w
22、hose volume is defined by two ring-shaped measuring marks, to flow laminarly through a capillary under the influence of gravity. As a result of the suspended level, the mean pressure head is independent of the filling volume, while the influence of surface tension (see DIN 53012) can generally be ne
23、glected. Table 1: Symbols, quantities and units s-1 mis2 Symbol Mean pressure head Y, m mm g Coverage factor (cf. DIN 131 9-3) Viscometer constant k K rn2k.2 mm2k.2 I n Capillary length Number of single measurements (flow times) in a measurement series Capillary radius R Re m mm m mm t Relative unce
24、rtainty of viscometer constant Temperature coefficient of kinematic viscosity u: K-i UV Flow volume Kinetic energy correction U m3 cm3 S e Relative difference between viscosities measured with two viscometers Kinematic viscosity Quantity m2is mm2is I SI unit I Other legal units Density of liquid She
25、ar stress at internal wall of capillary kg/m3 gicm3 Pa Acceleration due to gravity at the point of cal i brat ion I mis2 I Reynolds number Flow time S S Longest and shortest flow times in a series of n single measurements Relative uncertainty of viscosity Relative difference of flow times in a serie
26、s of measurements using one viscometer I) D, may also be used instead of i,. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 4 DIN 51 562-1 : 1999-01 Internal Flow Viscometer diameter of volume, in mm in cm3 size no. capillary, V, O 0,36 5,7 oc
27、 0,47 5,7 Oa 0,53 5,7 Viscometer Re for a iw for a rw for flow time flow e = i g/cm3 constant, Measuring range, Y, in mmW in s- IC, in mmVs of 200 s of 200 s, in Pa 0,001 wito i 500 6 200 1,3 0,003 0,7 to 3 130 2 800 1,7 0,005 1 to 5 70 1900 13 7 Theoretical basis of method The method is based on th
28、e following equation derived from the Hagen-Poiseuille law, taking account of the kinetic energy correction (also known as the Hagenbach correction; see DIN 5301 2): (4) v=K.(t-AtH).? g g For long flow times or greater viscometer sizes, At, may be disregarded (see clause 14). 8 Apparatus The followi
29、ng apparatus shall be used 8.1 Ubbelohde suspended level viscometer The viscometer (see figure 1) shall be made of 3.3 borosilicate glass as in IS0 3585 and consist of a ventilation tube (l), a capillary tube (2), a filling tube (3), an upper reservoir (4), a timing bulb (5), a capillary (6) which o
30、pens into the dome (7) of the suspended level bulb (8), an equalization tube (9) and a lower reservoir (1 O). The sample to be measured flows through the suspended level bulb from the capillary as thin film (suspended level) through the equalization tube back to the lower reservoir. The ventilation
31、tube shall be attached to the suspended level bulb at a point that is below the dome and sufficiently remote from the lower end of the capillary; this will ensure that the axial symmetry of the suspended level is not disturbed. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by In
32、formation Handling ServicesPage 5 DIN 51 562-1 : 1999-01 The filling marks (M,) indicate the quantity of sample to be poured in, while the measuring marks (M, and M2) delineate the samples flow volume and determine the mean pressure head. To compensate for the influence of surface tension, the ratio
33、 of the radius of the dome of the suspended level bulb to that of the timing bulb shall be 0,75l). The internal diameter of the equalization tube shall be large enough for equalization to effectively take place between the suspended level bulb and the lower reservoir, even in the case of high-viscos
34、ity liquids (.e. the ventilation tube remains open during measurement). The viscometer design specified here largely conforms to IS0 31 05, which also specifies dimensions that are not of metrological relevance. As the measuring range of a single viscometer is smaller than the overall measuring rang
35、e specified in clause 5, viscometers of various sizes are used to cover the entire range. These viscometers have different capillary diameters and, consequently, different constants; see table 2 for viscometer specifications. The actual viscometer constant shall not deviate from the values given in
36、table 2 by more than 1 O YO. Measuring marks, filling marks, the manufacturers name, viscometer size number and an identification number shall be permanently marked on the viscometer by the manufacturer. The viscometer shall be held in afixed position in the bath by means of a holder equipped with a
37、flat supporting plate at the top. The deviation of the capillary axis from the normal of this supporting plate shall not exceed 1 o (see subclause 8.4). 8.2 Temperature measuring device The device used to determine the temperature in the constant-temperature bath shall allow the measurement to be ca
38、rried out with an uncertainty of 0,02 “C. NOTE: These requirements are fulfilled, for example, by calibrated liquid glass thermometers having scale intervals of 0,Ol “C and a freezing point marking, with regard to the correction for the difference between the immersion depth during calibration and t
39、hat during measurement. For greater accuracy, calibrated platinum resistance thermometers are suitable. The temperature shall be measured as near as possible to the viscometer so that the requirements stipulated in subclause 8.4 are fulfilled. The temperature sensor should be immersed to a depth tha
40、t is 2/3 the depth of immersion of the viscometer and equal to the depth of immersion during calibration or verification. Adjustments shall be made, if necessary. The temperature measuring device shall be recalibrated or reverified at intervals appropriate for the type of thermometer and the operati
41、ng conditions. 8.3 Timing device The flow time can be measured using a timer (e.g. electronic stopwatch), by observing the passage of the meniscus, or by using an automatic timing device (cf. subclause 8.5). The smallest scale interval or digital increment displayed shall be no greater than 0,Ol s a
42、nd the relative uncertainty of the time measurement shall not exceed 0,02 YO. NOTE: These requirements are fulfilled by a calibrated timer having a smallest scale interval or digital increment The timer shall be recalibrated or reverified at intervals appropriate for the type of timer and the operat
43、ing conditions. of 0,Ol s. 8.4 Constant-temperature bath An automatically-controlled constant-temperature bath shall be used which is preferably capable of accom- modating several viscometers simultaneously. The top plate of the bath (used to support the upper plate of the viscometer holder) shall b
44、e flat, .e. it shall not deviate more than 1 o from the horizontal.2) The temperature of the bath liquid shall not vary by more than 0,02 “C during measurement. During the measurement, the temperature over the length of the viscometer shall not differ by more than 0,Ol “C from the measured bath temp
45、erature. NOTE: This can be checked, for example, by determining the temperature distribution in the bath -with the viscometer(s) in it - using a sufficiently sensitive temperature sensor that has been calibrated against the thermometer used to measure the bath temperature. The bath shall be protecte
46、d from direct sunlight or direct artificial light, since this may falsify the temperature reading. The thermometer and bath shall therefore be illuminated by low-radiation fluorescent tubes. l) See ASTM D 2162-79. 2, The plate may be adjusted by means of adjustment screws, and horizontality may be c
47、hecked with a spirit level. COPYRIGHT DIN DEUTSCHES Institut Fur Normung E.V.- EnglishLicensed by Information Handling ServicesPage 6 DIN 51 562-1 : 1999-01 12 3 J k -5 l M, O m T- 1 2 3 4 5 6 7 8 9 10 Ventilation tube Cap I lary tube Filling tube Upper reservoir Timing bulb Capillary Dome Suspended
48、 level bulb Equalization tube Lower reservoir M, and M, Measuring marks MF Filling marks Figure 1 : Ubbelohde viscometer (schematic) 8.5 Automatic measuring device The automatic measuring device used shall have a constant that has been determined by calibration. In this case, the measuring marks are
49、 optional, although any marks provided shall not interfere with the automatic detection of the passage of the meniscus. When using viscometers with ring marks, bear in mind that the viscometer constant referring to measurements made with the ring marks differs from that referring to automatic measurements. The latter is only valid when the automatic device is used for calibration. Automatic measuring devices that are also capable of automatically draining the old sample, cleaning the viscometer, and filling it with the new sample - and which thus have an additional rins
