There has been several portion control devices over the years. Some good, bad and of course - real ugly. The issue that confronts most of these products is that the manufacturer forgets the unit has to be cleaned. Most are not friendly in this respect. Another issue is that they are as good as the system set-up. Also, not very effecient with higher carbonated product. Try a search under beer portion control and review.
Scott Zuhse, Instructor
Micro Matic Dispense Institute