This work presents a new approach to correcting for concentration polarization (CP) in pressure-driven membrane measurements. In the existing test cells (both cross-flow and stirred-batch) there are distributions of extent of CP over membrane surface. This complicates the interpretation of experimental data. A novel design of test cell with equally-accessible membrane surface has been developed based on the classical configuration of rotating disk combined with the possibility of applying trans-membrane hydrostatic pressure differences of up to 20 bar. Due to the equal accessibility, corrections for CP can easily be made even in multi-ionic systems, which would be much more difficult with other membrane test cells. Since the membrane has to be sealed at the edge the geometry somewhat deviates from the ideal case of infinite disk. The impact of these deviations has been quantified via CFD simulations. A major part of the membrane surface is shown to be equally accessible while there are some expectable deviations close to the sealed membrane edge. This zone could be "screened" in the experiments. The approach could also be validated experimentally via studying the dependence of observed rejection on the rotation speed and demonstrating that intrinsic rejection was practically independent of it. Finally, to demonstrate the cell utility, we performed and interpreted a number of experiments using commercial NF270 membrane and various feed solutions (single salts and electrolyte mixtures). We conclude that this cell can be employed for systematic transport characterization of membranes and the obtained information can be used as input in the CFD modelling of membrane modules.