Comparing quantities to analyze charged fluctuations in heavy ion experiments, the dispersion of the charges in a central rapidity box was found to be best suited. Various energies and different nuclear sizes are considered in an explicit Dual-Parton-Model calculation using the DPMJET code and a randomized modification to simulated charge equilibrium. For large enough detection regions charged particle fluctuations can provide a signal of the basic dynamics of heavy ion processes.

PACS numbers: 25.75.Gz