ASTM D3709 Standard Test Method for Stability of Water-in-Oil Emulsions Under Low to Ambient Temperature Cycling Conditions
7. Procedure
7.1 After careful preparation of the sample to ensure homogeneity (described in Section 6), transfer 100 mL to a graduated 100-mL cylinder. Insert the vented stopper.
7.2 Place the cylinder in the cold box at -18 +/- 1.5°C (0 +/- 3°F) for a period of 16 h. Withdraw the cylinder from the cold box and allow to stand at room temperature, 21 +/- 3°C (70 +/- 5°F), for a period of 8 h.
7.3 Repeat the cycling procedure as in 7.2 for three more cycles.
7.4 Replace the cylinder in the cold box for a period of 64 h. Withdraw and allow to stand at room temperature for 8 h.
7.5 Repeat the cycling procedure as in 7.2 for four more cycles, except that during the final cycle, the period at room temperature is limited to 3 h instead of 8 h before making observations.
7.6 Observe and record the following:
7.6.1 The amount of oil separated, percent volume and
7.6.2 The amount of water separated, percent volume.
7.7 By means of a 10-mL pipet, withdraw aliquots in the following order.
7.7.1 With the pipet tip located exactly at the 80-mL mark, slowly withdraw a 10-mL sample and transfer to a small glass vial. This is designated as the upper layer sample.
7.7.2 With the pipet tip located exactly at the 15-mL mark, slowly withdraw a 10-mL sample and transfer to a small glass vial. This is designated as the lower layer sample.
7.8 Determine the water content, as percent weight, of the upper layer and lower layer samples, after shaking, by the procedure given in the Annex. Use a 0.05-mL sample transferred from the vials by means of a glass microsyringe.
