The round-bottom flask placed into a custom heater enables a hydrocarbon solvent to be boiled. The solvent vapors then immerse the rock sample removing water, gas, and oil from the sample. A water bath running over the cooling condensing tubes allows the water and solvent vapor to be cooled and liquefied. The water is collected in the graduated cylinder and the solvent returns to the round-bottomed flask to continue the distillation process.

This process allows for the direct determination of water saturation. Oil and gas saturation can be indirectly measured by measuring initial and dry weights. The distillation process cleans a sample removing all hydrocarbons and water from the sample.