  Three binary systems in the Hyades open cluster, with known metallicity and
good Johnson photometric data are used to test the validity of three
independent sets of stellar evolutionary tracks. A statistical method is
described and applied to the colour-magnitude diagram of the six selected
components, giving rise to $\chi^2$-contours in the age-metallicity plane. The
effects of the Hipparcos parallaxes on these confidence regions are studied for
these binaries through a comparison with very accurate but older orbital
parallaxes. Independent simultaneous age-metallicity estimates are given and
compared with observational constraints (see Lastennet et al. 1999,
astro-ph/9905273, for more details).
