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
5. Apparatus
5.1 Convection Oven, meeting the requirements of Specification E 145.
5.2 Graduated Cylinder - A stoppered 100-mL glass cylinder graduated in 1-mL increments. The stopper should have a vent groove to prevent pressure buildup during the test.
5.3 Pipet, 10-mL glass.
5.4 Microsyringe, 0.05-mL glass with a fixed needle, No. 19 gage, point style No. 3.
5.5 Glass Vials, approximately 30-mL size.
6. Preparation of Sample
6.1 To ensure uniformity of the sample, it should be mixed thoroughly before removing the quantity required for the test. Vigorous hand shaking or mechanical mixing for 3 to 5 min is recommended for litre-size containers or less.
6.2 Special difficulties arise in mixing and withdrawing representative samples from large containers. This is due to the nature of water-in-oil emulsions which are two-phase systems as distinct from truly homogeneous systems. Vigorous mechanical stirring for an extended period is the best means of achieving homogeneity. However, for unstable emulsions that have been in storage for some time, there is no satisfactory way to obtain a representative sample.
