Ion Exchange Demonstration Unit Technical Description Ion Exchange Demonstration Unit is a self-contained benchtop unit, which incorporates two vertical transparent tubes mounted on a panel. The tubes contain the respective cation and anion resins. A manifold arrangement allows the flow configuration to be changed. A rotameter, connecting hoses, a separate sump tank with suction pipe and pump for regenerant, test water or wash solutions complete the set-up. A conductivity meter connected to the outlet of the second ion exchange tube gives a continuous indication of the progress of demineralisation. The unit has been designed to demonstrate the use of ion-exchange resins for either continuous water softening or demineralisation.