A too small optical accessible area of the old Measurement Section of the Cavitation tunnel made monitoring the upcoming experiments, with for instance high speed cameras, impossible. This was its main imperfection. A proper amount of optical accessible area needed lead too this conversion. The new Measurement Section designed has an optical accessible area which is sufficient for the experiments. It was needed to have a zero velocity-, and pressure gradient over the new Measurement Section. The displacement thickness of the boundary layer which narrows effectively the inner of the Measurement Section would lead to acceleration of the flow and therefore needed to be compensated. This was done by gradually descending the bottom plate of the new Measurement Section over its length, since the side walls of the new Measurement Section had to be parallel for a constant distance of the camera to the side walls over its total length.