Only explosives which can be ignited by heat from the calorimeter's firing circuit can be tested in the oxygen calorimeter. Then very minute/small quantities are used for analysis. The calorific value of an explosive is not very high, but the burning speed is.
Therefore, it is not used frequently, but nevertheless, as a quality assurance tool for ignition caps and other heat ignitable substances. It is necessary to fill the vessel with any gas in order to close the valve, unless the "self-closing valve" option is ordered.
Solid rocket fuel is analyzed frequently in calorimeters: It is heat ignitable and has a high energy value.
Again, the vessel is NOT filled with oxygen, or is filled with nitrogen, thus emulating the fuel burning process. Data as to the calorific value (CV) of rocket fuel is closely guarded. Therefore, analysis should start with small quantities.