  The pseudogap phase above the critical temperature of high $T_{c}$
superconductors (HTSC) presents different energy scales and it is currently a
matter of intense study. The complexity of the HTSC normal state requires very
accurate measurements with the purpose of distinguishing different types of
phenomena. Here we have performed systematically studies through electrical
resistivity ($\rho$) measurements by several different current densities in
order to obtain an optimal current for each sample. This approach allows to
determine reliable values of the pseudogap temperature $T^{*}(n)$, the layer
coupling temperature between the superconductor layers $T_{LD}(n)$, the
fluctuation temperature $T_{scf}(n)$ and the critical temperature $T_{c}(n)$ as
function of the doping $n$. The interpretation of these different temperature
scales allows to characterize possible scenarios for the (Hg,Re) - 1223 normal
state. This method, described in detail here, and used to derive the
(Hg,Re)-1223 phase diagram is general and can be applied to any HTSC.
