PTB

The PTB, “Pompen TestBank”, or “Pumping TestBench”
Is a 12-meter-high tower the WOT uses for pump validation, the tower is a handy tool for this as it keeps the moving parts of the pump (the piston) at ground level and thus at an easy access height for the technician.
The extra height the tower provides makes for more challenging pump conditions than the 2.5m to 3.5m deep groundwater level that can naturally be found at the WOT-terrain.

The tower has been used in many experiments and has grown to include features for a variety of pumps:

-PTB (Pumping TestBench) A big transmission at the top of the tower (the big blue flywheel) translates the rotation of an electric motor into a linear pumping motion that can be used for traditional piston pumps (like used under many windmills or in lever based handpumps).

-TPTB (Ropepump TestBench) An additional motor with a variable transmission runs an electrically powered version of a rope pump, here different parameters for a ropepump can be tested (like: piston-size, speed, spacing, rope). At ground level a few meters of the pipe are transparent to allow spectators and technicians to see how the ropepump pistons function.

-ZPTB (Solarpump TestBench) At the bottom of the tower a new setup is being worked on. This setup will be used to test and quantify electric pumps with a focus on solar pumps. It uses a choke valve to stem the flow of water and thus simulate various pumping heights.

-Hydraulic rams 
The tower is also used to demonstrate different hydraulic rams, like the WOTs own Breurram. A series of valves is installed on the side of the tower to allow for various pumping heights (4m, 6m, 7.5m, 9.5m).