Prior to flow investigations in a real fuel cell manifold geometry, which is inaccessible with standard non-intrusive techniques, measurement data gained by MM-LDA need to be validated. For this, Particle Image Velocimetry (PIV) has been applied, which is another well-established laser-optical measurement technique. PIV measures local velocities in a two-dimensional measurement plane by detecting the movement of particles seeded to the fluid. However, this measurement technique requires two orthogonal optical accesses which may be hard to achieve in small geometries. Details on the PIV-technique can be found in Refs. [9] and [10]. For validation purposes velocity profiles were measured in a simplified model manifold using both PIV and MM-LDA.