In recent years, there has been an increasing demand for non-liquid nitrogen based cooling systems in thermal analysis because of environmental considerations and usability. Especially in differential scanning calorimetry (DSC), refrigerated cooling unit is often used. Using the Rigaku DSC, low temperature measurements from −90°C can be carried out. This indicates that refrigerated cooling can cover most DSC applications, and thus LN₂ cooling is only used for measuring a few limited materials.
Recently, Rigaku has developed the TMA8311/LR thermomechanical analyzer (TMA) with a refrigerated cooling unit. Previously, sub-ambient TMA measurement required LN₂ cooling, but the TMA8311/LR enables LN₂-free measurements thanks to the cooling system that achieves the lowest cooling temperature of −70°C, similar to the refrigerated cooling unit equipped DSC.