Measuring local currents in PE-fuel cells is an important tool for diagnostics and development. A semi-segmented cell has been developed, which can serve as a key instrument to investigate different phenomena in cells and stacks of technical relevance. Data with respect to water management is presented. These results show, that the local current distribution is strongly influenced by the dew point of the process air, the stoichiometry of the process air and the mode of operation. (c) 2005 Elsevier B.V. All rights reserved.