Abstract: There is provided a differential thermal analysis calorimeter for performing thermal hazard testing procedures which can be utilized as an ancillary plug-in device with commercial thermal analysis data acquisition systems. Simultaneous measurement of heat flow of sample reactants and direct measurement of sample pressure is provided during a reaction within a substantially hollow furnace enclosure defining a heated zone having a heated top plate. A pair of longitudinally elongated heat conductive sample and reference tubes having upper and lower ends are each connected to the top plate adjacent their respective upper ends. The tubes depend downwardly from the top plate within the hollow furnace enclosure, and are heated by the heating means, whereby heat is conducted to the lower end of each tube longitudinally therealong. A pressure transducer is connected adjacent the upper end of the sample tube for directly measuring the pressure in the sample tube within the heated zone of the furnace.

Abstract: Scientific apparatus and a method are described for observing simultaneously both structural and thermodynamic properties of materials. An X-ray diffractometer and a thermal analyzer and mounted to cooperate and coact on the same sample and to complete a meaningful analysis in a very few minutes. The diffractometer is equipped with a rapid position-sensitive detector connected to a multichannel analyzer to record and display X-ray diffraction data from the sample over an angle of 20.degree. (two theta) or more. The thermal analyzer is preferably a differential scanning calorimeter. By correlating X-ray diffraction and thermal data taken simultaneously while the sample is passing through a range of temperatures and/or environments, structural changes corresponding to thermal events can be identified and elucidated.