  We study fluctuations of the conductance of micron-sized graphene devices as
a function of the Fermi energy and magnetic field. The fluctuations are studied
in combination with analysis of weak localization which is determined by the
same scattering mechanisms. It is shown that the variance of conductance
fluctuations depends not only on inelastic scattering that controls dephasing
but also on elastic scattering. In particular, contrary to its effect on weak
localization, strong intervalley scattering suppresses conductance fluctuations
in graphene. The correlation energy, however, is independent of the details of
elastic scattering and can be used to determine the electron temperature of
graphene structures.
