The method of inspection in which the decision about the suitability of the object is undertaken on the basis of the measurement results was considered. The reliability of decision depended on the real processing characteristics of the measurement system. The non-ideal characteristics of the system at border values of a tolerance range (non linearity, decreased sensitivity) increased the effect of random distribution of examd. parameter on the decision correctness. An improved method was based on calibration in 2 points of the tolerance interval of controlled parameters by converting the proc. characteristics of the system into the nominal limits in several cycles of 2 multiplicative and additive stages. The type and no. of cycles was based on an anal. of the relationship between components of a proc. error of the measuring system and the length of tolerance range.