ASTM D3709 Standard Test Method for Stability of Water-in-Oil Emulsions Under Low to Ambient Temperature Cycling Conditions
8. Report
8.1 Report the results as follows:
8.1.1 Oil separation, percent volume,
8.1.2 Water separation, percent volume,
8.1.3 Upper layer water content, percent weight, and
8.1.4 Lower layer water content, percent weight.
9. Precision and Bias
9.1 The precision (see Note 1) of this test method is dependent on the degree of instability brought about by the temperature cycling process.
9.1.1 Type I - Stable Emulsions (Procedures A and B):
9.1.1.1 Precision - The precision of the method as determined by the statistical examination of interlaboratory test results is as follows.
9.1.1.2 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty. (See Table 1.)
9.1.1.3 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, exceed the following values only in one case in twenty. (See Table 1.)
NOTE 1 - Precision limits are based on a round-robin test program carried out in Technical Division N in 1977 using invert emulsion samples with water contents between 35 and 50 % (weight). Eleven cooperators tested five samples representing highly stable, borderline, and unstable emulsions.
9.1.2 Type II - Unstable Emulsions - Results can vary widely on samples which show any degree of instability brought about by temperature cycling and no precision limits can be set.
9.1.3 Bias - No bias statement is possible because there is no absoute value. The results are interpretable only with respect to this test.
10. Keywords
10.1 emulsions; water separation; oil separation
