APPLICATION OF DSC WITH ATMOSPHERIC CONTROL IN THERMAL HAZARD EVALUATION - A DISCUSSION OF THE SOURCES OF ERROR

Since differential scanning calorimetry is a dynamic temperature technique, there are several factors which can affect the resulting experimental curves. For example, it is well known that changing from nitrogen to air atmosphere can create additional exothermic peaks. However, during routine determinations into closed pans, the influence of static air remaining in the crucible is often forgotten. The aim of this paper is to emphasize the importance of performing such tests in a completely inert atmosphere; even minimal traces of air can cause misinterpretations and consequently the use of unnecessary safety measures that could penalize the process. A simple device that allows crucibles to be closed directly in an inert atmosphere, is described.