  Various measures of charge fluctuations in heavy-ion collisions are
discussed. Advantages of the Phi-measure are demonstrated and its relation to
other fluctuation measures is established. To get the relation, Phi is
expressed through the moments of multiplicity distribution. We study how the
measures act in the case of a `background' model which represents the classical
hadron gas in equilibrium. The model assumes statistical particle production
constrained by charge conservation. It also takes into account both the effect
of incomplete experimental apparatus acceptance and that of tracking
inefficiency. The model is shown to approximately agree with the PHENIX and
preliminary STAR data on the electric charge fluctuations. Finally,
`background-free' measures are discussed.
