ASTM D3707 test method for storage stability of water-in-oil emulsions
ASTM D3707 standard test method for storage stability of water-in-oil emulsions by the oven test method
9. Report
9.1 Since the test can be performed on the basis of 48 h in the oven (Procedure A) or 96 h (Procedure B), the report is to indicate the procedure followed.
9.2 Report the results as follows:
9.2.1 Oil separation, percent volume,
9.2.2 Water separation, percent volume,
9.2.3 Upper layer water content, percent weight, and
9.2.4 Lower layer water content, percent weight.
10. Precision and Bias
10.1 The precision (Note 3) of this test method is dependent on the degree of stability of the emulsion, as follows:
10.1.1 Type I - Stable Emulsions (Procedures A and B):
10.1.1.1 The precision of the test method as determined by the statistical examination of interlaboratory test results is as follows.
10.1.1.2 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.)
10.1.1.3 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 3 - 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.
10.1.2 Type II - Highly Unstable Emulsions - The precision limits for the 96-h test are of the same order as for Type I. The 48-h test would be less severe and less precise.
10.1.3 Type III - Emulsions of Borderline Stability - No precision limits can be set since the change in the sample stability with time or conditions, or both, of handling make it impractical to determine meaningful precision limits.
10.2 Bias - No bias statement is possible because there is no absolute value. The results are interpretable only with respect to this test.
11. Keywords
11.1 emulsions; water separation; oil separation
