ASTM D4006 standard test method for water in crude oil by distillation
3. Summary of Test Method
3.1 The sample is heated under reflux conditions with a water immiscible solvent which co-distills with the water in the sample. Condensed solvent and water are continuously separated in a trap - the water settles in the graduated section of the trap, and the solvent returns to the distillation flask.
4. Significance and Use
4.1 A knowledge of the water content of crude oil is important in the refining, purchase, sale, or transfer of crude oils.
