Low boundary values for the emissions of noxious matters are a great technical challenge for the producer of internal combustion engines. The optimization of complex procedures for mixing and combustion require a detailed knowledge beyond our present-day state of knowledge. The measuring techniques presented, based on the principles of laser-induced fluorescence, contribute to making these procedures visible and comprehensible. It is thereby a declared aim not to carry out the investigations under ideal test conditions, but to realize the application of the measuring techniques on real experimental carriers