The determination of the fundamental atmospheric parameters of stars remains
an everlasting preoccupation of most stellar astronomers. The imminent release
of the Hipparcos results certainly makes this problem especially acute.
On the other hand, new and hopefully more realistic atmosphere models have
become available in the last few years (Kurucz 1991, 1993, 1994),
as well as a large amount of precise,
homogeneous [Fe/H] values (Edvardsson et al. 1993). We
found it worthwhile, therefore, to revise the already published calibrations
(North & Nicolet 1990, hereafter NN90; Kobi & North
1990, hereafter KN90) and to take this opportunity to
fill the gap that existed for stars with effective temperatures between 8500
and about 10500 K. The efficiency of the Geneva system is similar to that of
the widely-used 
one, so it would be a pity not to exploit it fully.
The only drawback of the Geneva system, compared to the 
one, is its
sensitivity to interstellar reddening for A and cooler stars.
In the following, we shall present successively the three temperature domains
which are treated separately (as in the 
system), discussing
together the reference (or standard) stars and the theoretical grids. The possible applications and limits of this calibration are discussed in the
conclusion.