Originally Posted by northstate
depending on your budget, get a refrigerant recovery scale (TIF9010A) to measure the whole packed extractor unit and your recovery/storage tank to know for sure. The maths don't lie, you can also get a yield estimate in % too after you weigh your final product
A good point! An important tool!
A refrigerant recovery scale will tell you when your solvent storage tank has been fully transferred, as well as when the liquid phase has been fully recovered.
You will always have a vapor (gas) phase in the space above the liquid. A refrigerant pressure gauge will tell you when the pressure is at or below one atmosphere, or zero gauge.
If the LPG is a mixture, while the liquid phase stays mixed, the vapor phase above the liquid will be enriched in the lowest boiling point constituent.
Losing those vapors when you open the system each time, changes the LPG liquid gas ratio through fractional distillation.