[en] The principal task of our studies is to provide a rational interpretation of the thermodynamic and fluid dynamic events taking place in a closed vessel upon detonation of an explosive charge and subsequent turbulent combustion of its products, acting as fuel for an exothermic reaction with air. Under such circumstances, the latter has been compressed by a reverberating shock front of the blast wave generated by the explosion. The paper presents the chemical and thermodynamic background and its numerical results, deduced for this purpose from mass spectroscopic data and pressure records, acquired upon explosion of a 0.8 kg charge of TNT in a 17 m³ chamber filled with air--a diagnostic analysis identified by the title. The evolution of the flow field and its structure are presented in a companion paper