This instrument is used for separating and determining the content of water, oil, and solid phases in drilling fluid samples. A certain amount of drilling fluid sample is heated in the distillation apparatus, evaporating the liquid components, which are then condensed and collected in a graduated cylinder. The volume of the liquid is determined from the readings of the oil and water phases in the cylinder, and the total solid phase volume (suspended and dissolved) is obtained from the difference (total sample volume minus liquid phase volume). To determine the volume of suspended and dissolved solids in the distillation apparatus, certain calculations must be performed, and the relative volume of solids and materials with low specific gravity can also be calculated.