DSC / Differential Scanning Calorimetry

Differential Scanning Calorimetry, DSC, is a technique that is widely used to measure thermal transitions like melting, crystallization and glass transition. It monitors the heat that is absorbed or emitted by a sample in order to keep the temperature the same as that of a reference sample. This way all the thermal transitions that take place as a result of chemical or physical changes can be monitored while the sample is cooled or heated.

The setup is simple and is based on two individually heated pans connected to sensors as shown in the Figure. One pan is the reference pan and the other is the sample holder. The operating principle is based on maintaining the same temperature in both samples. When the material undergoes a transition, heat is either emitted or absorbed (depending on whether the transition is exothermic or endothermic) leading to a change in the sample’s temperature. Any change in the sample’s temperature results in the resistor to channel more or less energy in order to maintain the sample temperature similar to that of the reference. The rate at which the resistor provides power to the sample compared to that of the reference sample gives us information about the transition of the material. The extra energy supplied by the resistor is equal to the heat of fusion ΔΗ needed for the sample to make this transition.