The quality function of the period fits in terms of the effective temperature for the PG 1159 sequences with different stellar masses (in solar units) corresponding to the case in which the observed periods are assumed to be associated to dipole (ℓ = 1) and quadrupole (ℓ = 2) modes. We note the presence of two strong minimum compatible with the effective temperature of the star, corresponding to M_⋆ = 0.589 M_⊙ and T_eff = 118 655 K, and M_⋆ = 0.741 M_⊙ and T_eff = 115 203 K.