  Charge fluctuations observed in early fixed-target proton-proton experiments
are consistent with string models. In central heavy ion events the picture can
change in two ways: strings can interact and find new ways to hadronize or they
can be effectively inactivated to lose their dynamical role as ordering
mechanism. Widely different charge fluctuations can be expected. The dispersion
of the charges in a central rapidity box is an advantageous measure. In an
explicit Dual-Parton-Model calculation using the DPMJET code and a randomized
modification to simulated charge equilibrium, various energies and different
nuclear sizes were considered. Local fluctuations were found to be a serious
problem. However, for large enough detection regions charged particle
fluctuations can provide a clear signal reflecting the basic dynamics of
central heavy ion processes.
