Record the first time when the temperature changed during the experiment. The first section of the graph should show a constant temperature, the boiling point of the component that has the lower boiling point between the two liquids. Because the temperature stays consistent, you know a relatively pure liquid is distilling during this time.
Note the volume, amount of drops, when the temperature begins to rise after being constant for a period of time. When the temperature begins to rise, the two liquids are mixing. The second liquid with the higher boiling point is beginning to distill--this does not immediately happen and must mix with the first liquid as the temperature rises. For example, if the first liquid's boiling point is 70 degrees Fahrenheit and the second liquid's boiling point is 100 degrees Fahrenheit, it might take 10 drops of distilled liquid to reach the higher boiling point. If your distillation rate is one drop every 30 seconds, the liquids will mix for approximately five minutes before the second liquid begins to purely distill.
Record the temperature and amount of drops it takes for the graph to plateau and stay constant a second time. The temperature indicates the boiling point of the second component. Subtract the number of drops used to reach the second boiling point by the amount of drops noted in Step 2, when the temperature first begin to rise. The answer indicates the amount of volume where the two liquids are mixed before the second liquid purely distills.