Quantitative criteria to ascertain the quality of calorimetric models based on physical parameters are presented. These include not only a comparison between model and experimental pulse responses, especially for the larger time constants, but also an analysis of their spectra up to the frequential limit brought about by the experimental noise. A calorimetric model based on the physical parameters of a Unipan 600 calorimeter is used to reconstruct a given power dissipation. The results are then compared to those given by other methods, i.e. dynamic optimization, inverse filtering and harmonic analysis.