Hydraulicity 7: Head Measurements
The PerPump, aka Fountain of Heron, shown pumping 8 inches or so of pressure head, and several configurations are compared. A common drinking straw is placed over the pipette output and sealed against the bottom of the cup by pressing it into the pipette mounting adhesive bead. The pressure head can be seen to rise in the straw until the pump tops out. The best performance was 8 1/4 inches of head, above the base of the cup, and this occurred with the down tube in place and the flow restrictor in line. The worst performance was almost three inches less, by the chamber with the empty riser and ringwall. I filled the green bottle input reservoir and cup to the same level for each trial and waited until the level in the input reservoir reached the same mark, then I measured the pressure head at the output pipette. Don’t worry…. right now the TinselZed floater and ringwall are inert, I am just seeing what water levels are required. When they are properly plumbed in to utilise the pressure advantage– if there is one– , I believe the pumping head may be increased. We shall see what we shall see.