Phase Transistions

Phase transition determination by Differential Scanning Calorimeter (DSC)

If a compound changes its state during temperature increase or decrease, or if a solid changes its (crystal)structure, this phenomena is called phase transition. The most simple example for a phase transition is melting or crystallization. All these processes can be easily monitored by DSC because they always take place releasing energy to (exothermic) or consuming energy from (endothermic) the environment in form of temperature changes. DSC measures these temperature changes using one (or more) thermocouple that is attached to the sample holder and can compare the exact sample temperature with the temperature of the environment as well as with a reference sample. The difference between reference and sample can show, if there is an endothermic or exothermic process taking place, depending on the algebraic sign of the energy value that is resulting. The exact position of an effect if monitored over temperature additionally shows very accuratly when it is taking place. The precision of measuring the sample temperature determines the resolution and sensitivity of the whole DSC experiment.