D NOTE 4—Dip cups are not recommended for use with thixotropic time dependent materials but if used for them such as gravure or exographic inks , more vigorous agitation will be necessary to break up the structure before the measurement is made. This committee is not aware of any other source for ow cups having properties similar enough to the Shell cup to be included in this test method. Record the temperature of the efflux stream. NOTE 5—The cup should not be held by the loop handle during the measurement process. If the test material is non-Newtonian, for example, shear-thinning or thixotropic, another method, such as Test Methods D , should be used. A diagram of a Zahn cup is given in Fig. Precision and Bias
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The dimensions, including orices, are only approximate because the cups are not made to a uniform specication. Your comments will astm d4212 careful consideration at a meeting of the responsible technical committee, which you may attend.
Temperature drift during the test should be kept to a minimum.
Zahn Cup | ASTM D | ASTM D | ASTM D
This test method is recommended for viscosity control work within one plant or laboratory and should be used to check compliance with specifications only when sufficient controls have been instituted to ensure adequate comparability of results.
The product of the factor and an efflux time gives a astm d4212 viscosity in Zahn or Shell seconds. Most manufacturers equip the cup with a ring through the loop handle.
In such astm d4212 application ashm viscosity at With this curve, a viscosity determined at one measured temperature may be converted quickly to a viscosity at another temperature. Because of their greater mass, Shell cups should remain in the uid for the full 5 min.
Seta Zahn Cup No. 3
For careful work, the temperature should be taken in the efflux stream, but for process control such as monitoring a dip tankthis is not necessary. It is common to make only a single measurement, but for greater precision and accuracy astm d4212 mean of two or astm d4212 measurements should be taken. Cup variations are not a problem for consistent control of a bath or tank as long as appropriate comparisons are made with old cups, if required, to maintain continuity of data.
The values given in parentheses are for information only. If the test material is nonNewtonian, for example, shear-thinning or thixotropic, another method, such as Test Methods Dshould be used. See Table 1 for viscosity ranges for the various cups. It is recommended that the uid and the cup be held at the test temperature for at least 15 min prior to testing. Precision and Bias Summary of Test Method 4.
Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. The linear equations have been chosen because it is much more straightforward to make time corrections based on linear equations than on nonlinear ones and they are adequate for most applications. Astm d4212 to Active This link will always route to the current Active version of the standard.
Under controlled conditions, comparisons of the viscosity of nonnewtonian materials may be helpful, but viscosity determination methods using controlled shear rate or shear stress are preferred. As the top edge of astm d4212 cup breaks the surface, start the timer. Under controlled conditions, comparisons of the viscosity of non-newtonian materials may be helpful, but viscosity determination methods using controlled shear rate astm d4212 shear stress are preferred.
Allow the cup to remain in the uid for 1 to 5 min to attain thermal equilibrium. The frequency of this depends upon the amount of use and care that the individual cup receives, and the level of precision required.
Originally published as D — If the test material is non-Newtonian, for example, shear-thinning or thixotropic, another method, such as Test Methods Dshould be used. Zahn cup nonlinear equations that better t viscosity curves for some cups better may be found in the literature. Astm d4212 the time of efflux to the nearest 0. Techniques for ensuring continued calibration of dd4212 that do not claim compliance with these formulas include; comparison of current ow times for a standard uid against the original ow time, and comparison against a veried standard cup.
ASTM D – 16 Standard Test Method for Viscosity by Dip-Type Viscosity Cups
If the ratio of shear stress to shear rate is not constant, the liquid is nonNewtonian. The efflux time in seconds constitutes the viscosity. Each manufacturer produces d422 different cup and considerable variation between batches from some manufacturers has been astm d4212 in the past. The correction factor is equal to original standard—uid efflux time divided by the current one.
Stir or agitate the uid well to give uniform temperature and density. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.