Described is a method for producing thermoplastic material containers by blow-molding or stretch-blow-molding a hollow body previously heated in an oven and placed in a mold. The method includes a preliminary calibration step of: producing containers on the basis of first control parameters; measuring the wall thickness on extraction from the mold at two or more different heights; storing a reference thickness in a memory unit; modifying at least one control parameter; measuring the wall thickness at two or more different heights after the modification of each control parameter; storing the thicknesses; comparing said stored measured thicknesses with theoretical thicknesses that would have been obtained after modification of the control parameter(s) according to predetermined correction coefficients; and modifying the predetermined correction coefficients so that the thicknesses measured after modification of the control parameter(s) correspond to the theoretical thicknesses that would have been obtained with the aforementioned predetermined coefficients.

A method and apparatus for shaping plastic preforms into plastic containers, wherein at least three different pressure stages are applied to the plastic preforms in order to expand them, wherein the pressure stages are provided by at least three different compressed-air reservoirs, and wherein, additionally, the plastic preforms are stretched in their longitudinal direction by stretching rods, wherein compressed air is returned at least at times from the plastic containers to at least one compressed-air reservoir, and at least one value characteristic of the consumption of compressed air is detected.