  Using derived previously effective theory we explore conductance in the
Luttinger model with one impurity.
  A new approach to the renormalization group (RG) analysis of this model is
developed. It is based on the original Gell-Mann-Low formulation of RG. We sum
up infrared logarithmic contibutions to conductance in the leading and few
subsequent approximations. We analyze the validity of widely used ``poor
man's'' scaling approach and find that it is applicable only in the leading
approximation. Our results for corrections to this approximation are different
from results obtained in other papers.
  It should be expected beforehand, as Gell-Mann-Low function of the model is
not regularization scheme invariant. For this reason the observed quantity
(e.g., conductance) can not satisfy the Gell-Mann-Low equation beyond the
"leading-log"\ approximation as it is supposed in the "poor man's" approach.
  We formulate the method to calculate the conductance from renormalized
hamiltonian in the post-leading approximations and match results to the case of
weak impurity where the answer is known in any order in electron-electron
interaction.
