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1、STD-IS0 31OLi-ENGL 199i = 4851703 071571l 175 INTERNATIONAL STANDARD IS0 3104:1994 TECHNICAL CORRIGENDUM 1 Published 1997-07-1 5 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEVHAPO annex A gives further guidance. Automated viscometers, which have been shown to measure kinematic viscosity within t
2、he limits of pre- cision given in clause 14, are acceptable alternatives. Apply a kinetic energy correction (see IS0 3105) to kinematic viscosities less than 10 mm2/s and flow times less than 200 s. 6.2 Viscometer holder, enabling all viscometers which have the upper meniscus directly above the lowe
3、r meniscus to be suspended vertically within 1“ in all directions. Those viscometers whose upper meniscus is offset from directly above the lower meniscus shall be suspended vertically within 0,3“ in all directions (see IS0 3105). NOTE 7 The proper alignment of vertical parts may be confirmed by usi
4、ng a plumb line, but for rectangular baths with opaque ends this may not be wholly satisfactory. 6.3 Temperature-controlled bath, containing a transparent liquid of sufficient depth such that at no time during the measurement is any portion of the sample in the viscometer less than 20 mm below the s
5、urface of the bath liquid or less than 20 mm above the bottom of the bath. Temperature control of the bath liquid shall be such that, for each series of flow-time measurements, within the range of 15 “C to 100 “C the temperature of the bath medium does not vary by more than f 0,02 “C from the select
6、ed temperature over the length of the viscometer, or between the position of each viscometer, or at the location of the thermometer. For temperatures outside this range, 5.4 Water, deionized or distilled, conforming to the deviation from the desired temperature shall not Grade 3 of IS0 3696. Filter
7、before use. exceed f 0,05 “C. 5.3 Drying solvent, volatile and miscible with both the sample solvent (5.2) and water (5.4). Filter before use. NOTE 5 Acetone is suitable. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standar
8、ds 1/9972545001 Not for Resale, 04/20/2007 02:31:23 MDTNo reproduction or networking permitted without license from IHS -,-,- 8 IS0 IS0 3104 94 W 4851903 0576493 401 W IS0 3104:1994(E) 6.4 Temperature-measuring device, for the range O “C to 100 O C , either calibrated liquid-in-glass thermometer (an
9、nex B) of an accuracy after cor- rection of f 0,02 “C or better, or any other thermometric device of equal or better accuracy. When two thermometers are used in the same bath, they shall agree within 0,04 “C. NOTE 8 If calibrated liquid-in-glass thermometers are used, the use of two thermometers is
10、recommended. Outside the range O “C to 100 “C, a calibrated liquid- in-glass thermometer of an accuracy after correction of f 0,05 “C or better shall be used, and when two thermometers are used in the same bath they shall agree within f 0,l O C . 6.5 Timing device, capable of taking readings with a
11、discrimination of 0,l s or better, and having an ac- curacy within 0,07 % (see annex C) of the reading when tested over intervals of 200 s and 900 s. NOTE 9 Electrical timing devices may be used if the cur- rent frequency is controlled to an accuracy of 0,05 % or better. Alternating currents, as pro
12、vided by some public power systems, are intermittently rather than continuously controlled. When used to actuate electrical timing devices, such control can cause large errors in viscosity flow measurements. 7 Calibration and verification 7.1 Verify the viscometer calibration following the laborator
13、y procedure using a certified viscosity refer- ence standard (5.5). If the measured kinematic vis- cosity does not agree within f 0,35 % of the certified value, recheck each step in the procedure, including thermometer and viscometer calibrations, to locate the source of error. Table 1 in IS0 3105 g
14、ives details of standards available. NOTE 10 The most common sources of error are caused by particles of dust lodged in the capillary bore and tem- perature measurement errors. It should be appreciated that a correct result obtained on a standard oil does not preclude the possibility of a counterbal
15、ancing combination of the possible sources of error. 7.2 The calibration constant, C, is dependent upon the gravitational acceleration at the place of calibration and this shall therefore be supplied by the standard- ization laboratory, together with the instrument con- stant. Where the acceleration
16、 of gravity, g, differs by more than 0,l %, correct the calibration constant as f o I lows: where the subscripts 1 and 2 indicate respectively the standardization laboratory and the testing laboratory. 8 General procedure for kinematic viscosity determination 8.1 Adjust and maintain the viscometer b
17、ath at the required test temperature within the limits given in 6.3, taking account of the conditions given in annex B and of the corrections supplied on the cer- tificates of calibration for the thermometers. Thermometers shall be held in an upright position under the same conditions of immersion a
18、s when calibrated. NOTE 11 In order to obtain the most reliable temperature measurement, it is recommended that two thermometers with valid calibration certificates be used (see 6.4). They should be viewed with a lens assembly giving approximately x 5 magnification and be arranged to eliminate paral
19、lax er- rors. 8.2 Select a clean, dry, calibrated viscometer having a range covering the estimated kinematic viscosity (that is, a wide capillary for a very viscous liquid and a narrower capillary for a more fluid liquid). The flow time shall not be less than 200 s or the longer time noted in IS0 31
20、05. NOTE 12 The specific details of operation vary depend- ing on the type of viscometer. The operating instructions for the different types of viscometers listed in tableA.l are given in IS0 3105. 8.2.1 When the test temperature is below the dew point, affix loosely-packed drying tubes to the open
21、ends of the viscometer. The drying tubes shall fit the design of the viscometer and not restrict the flow of the sample by pressures created in the instrument. Carefully flush the moist room air from the viscometer by applying vacuum to one of the drying tubes. Finally, before placing the viscometer
22、 in the bath, draw up the sample into the working capillary and timing bulb and allow to drain back, as an additional safeguard against moisture condensing or freezing on the walls. 8.2.2 Viscometers used for silicone fluids, fluorocarbons and other liquids which are difficult to remove by the use o
23、f a cleaning agent shall be re- served for the exclusive use of those fluids, except during their calibration. Subject such viscometers to calibration checks at frequent intervals. The solvent washings from these viscometers shall not be used for the cleaning of other viscometers. 3 Copyright Intern
24、ational Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/20/2007 02:31:23 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 3104 94 m 4853903 0576492 348 W IS0 3104:1994(E) 0 IS0 9 De
25、termination of transparent liquids viscosity of 9.1 Charge the viscometer and place in the bath in the manner dictated by the design of the instrument, this operation being in conformity with that employed when the instrument was calibrated. If the sample contains solid particles, filter during char
26、ging through a (75 pm) filter (see IS0 3105). NOTE 13 In general, the viscometers used for trans- parent liquids are of the type listed in tableA.l, types A and B. 9.2.2 If the two measurements agree with the stated determinability figure (see 14.1) for the prod- uct, calculate the average of the tw
27、o measurements and use this value to calculate the kinematic viscosity. If the measurements do not agree, repeat the deter- mination after thorough cleaning and drying of the viscometer and filtering of the sample. Record the result. 10 Determination of viscosity of opaque liquids 10.1 For steam-ref
28、ined cylinder oils and black lubri- cating oils, proceed to 10.2 ensuring a thoroughly representative sample is used. For residual fuel oils and similar waxy products, whose kinematic viscosity can be affected by thermal histo, the proce- dure described in 10.1.1 to 10.1.6 shall be followed to minim
29、ize this effect. 9.1.1 With certain products which exhibit “gel-like“ behaviour, take care that measurements are made at temperatures sufficiently high for such materials to flow freely, so that similar kinematic viscosity results are obtained in viscometers of different capillary di- ameter. 9.1.2
30、Allow the charged viscometer to remain in the bath long enough to reach the test temperature. Where one bath is used to accommodate several vis- cometers, never add or withdraw a viscometer while any other viscometer is being used to measure flow time. Because time in the bath will vary for differen
31、t in- struments, for different temperatures and for different kinematic viscosities, establish a safe equilibrium time by trial. NOTE 14 30 min should be sufficient, except for the highest kinematic viscosities. 9.1.3 Where the design of the viscometer requires it, adjust the volume of the sample to
32、 the mark after the sample has reached temperature equilibrium. 9.2 Use suction (if the sample contains no volatile constituents) or pressure to adjust the head level of the test sample to a position in the capillary arm of the instrument approximately 7 mm above the first timing mark, unless any ot
33、her value is stated in the operating instructions for the viscometer. With the sample flowing freely, measure, in seconds to within 0,l s (see 6.5), the time required for the meniscus to pass from the first to the second timing mark. If this flow time is less than the specified minimum (see 8.2), se
34、lect a viscometer with a capillary of smaller diam- eter and repeat the operation. 9.2.1 Repeat the procedure described in 9.2 to make a second measurement of flow time. Record the re- sult. NOTE 15 In general, the viscometers used for opaque liquids are of the reverse-flow type listed in tableA.l,
35、type C. 10.1.1 Heat the sample in its original container, in an oven, at 60 “C f 2 “C for 1 h. 10.1.2 Thoroughly stir the sample with a suitable rod of sufficient length to reach the bottom of the con- tainer. Continue stirring until there is no sludge or wax adhering to the rod. 10.1.3 Recap the co
36、ntainer tightly and shake vigor- ously for 1 min to complete the mixing. NOTE 16 With samples of a very waxy nature or samples of high kinematic viscosity, it may be necessary to increase the heating temperature above 60 “C to achieve proper mixing. The sample should be sufficiently fluid after heat
37、ing for ease of stirring and shaking. 10.1.4 Immediately thereafter pour sufficient sample to fill two viscometers into a 100 ml glass flask and loosely stopper the flask. 10.1.5 Immerse the flask in a bath of boiling water for 30 min. NOTE 17 Care should be taken, as vigorous boil-over may occur wh
38、en opaque liquids which contain high levels of water are heated to high temperatures. 10.1.6 Remove the flask from the bath, stopper tightly and shake for 1 min. 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972
39、545001 Not for Resale, 04/20/2007 02:31:23 MDTNo reproduction or networking permitted without license from IHS -,-,- 0 IS0 10.2 Charge two viscometers and place in the bath in the manner dictated by the design of the instru- ment. For example, for the cross-arm or the BS U- tube viscometers for opaq
40、ue liquids, filter the sample through a 75 pm filter into two viscometers previously placed in the bath. For samples subjected to heat pretreatment (10.11, use a preheated filter to prevent the sample coagulating during the filtration. NOTE 18 Viscometers which are charged before being inserted into
41、 the bath may need to be preheated in an oven prior to charging the sample. This is to ensure that the sample will not be cooled below test temperature. 10.2.1 After 10 min in the bath, adjust the volume of the sample (where the design of the viscometer requires) to coincide with the filling marks a
42、s in the viscometer specifications (see IS0 31 05). 10.2.2 Allow the charged viscometers enough time in the bath to reach the test temperature. (See note 14.) Where one bath is used to accommodate several viscometers, never add or withdraw a viscometer while any other viscometer is being used to mea
43、sure flow time. 10.3 With the sample flowing freely, measure, to the nearest 0,l s (see 6.51, the time required for the advancing ring of contact to pass from the first timing mark to the second. Record the result. In the case of samples requiring heat pretreatment (10.11, complete the determination
44、s within 1 h of completing the pretreatment. 10.4 Calculate the mean kinematic viscosity, v, in mm2/s, from the two determinations. For residual fuel oils, if the two measurements agree within the stated determinability figure (see 14.11, calculate the average of the two measurements and use this va
45、lue to calculate the kinematic viscosity to be reported. If the measurements do not agree, re- peat the determination after thorough cleaning and drying of the viscometer and filtering of the sample. Record the result. NOTE 19 available. For other opaque liquids, no precision data is 11 Cleaning of
46、the viscometer 11.1 Between successive determinations, clean the viscometer thoroughly by several rinsings with the sample solvent (5.21, followed by the drying solvent IS0 3104: 1994(E) (5.3). Dry the tube by passing a slow stream of filtered dry air through the viscometer for 2 min or until the la
47、st trace of solvent is removed. 11.2 Periodically clean the viscometer with the cleaning solution (CAUTION - see 5.1) for several hours to remove residual traces of organic deposits, rinse thoroughly with water (5.4) and drying solvent (5.31, and dry with filtered dry air or a vacuum line. Remove an
48、y inorganic deposits with hydrochloric acid treatment before the use of cleaning solution, par- ticularly if the presence of barium salts is suspected. 11.3 Alkaline cleaning solutions shall not be used, as changes in the viscometer calibration may occur. 12 Calculation 12.1 Calculate the kinematic
49、viscosity, Y, from the measured flow time, t, and the viscometer constant, C, by means of the following equation: v = C x t where v is the kinematic viscosity, in square milli- metres per second; C is the calibration constant of the viscometer, in square millimetres per sec- ond squared mm2/s*; is the mean flow time, in seconds. t 12.2 Calculate the dynamic viscosity, q, from the calculated kinematic viscosity, v, and the density, p , by means of the fo
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