Precise Measurements of the Specific Heat Capacity

The c_p investigations in the region of phase changes can be roughly divided into two classes: costly and time-consuming precision measurements using adiabatic or 'alternating current' (AC) calorimetry, and survey measurements using conventional DSC. The purpose of this work is to show that 'temperature modulated ' DSC (TMDSC) provides an excellent alternative to the precision methods. Two substances, potassium dihydrogen phosphate (PDP) and strontium titanate (SrTiO₃), were chosen as models to test the quality of a modified METTLER TOLEDO DSC821^e calorimeter with ADSC option. The results show that the TMDSC technique is very reliable, even at medium-low temperatures, for the investigation of phase transitions in the condensed phase, as long as the cooling of the measurement system is sufficiently stable.

^{Precision measurements of the specific heat capacity with the temperature modulated DSC (TMDSC) at lower temperatures | Thermal Analysis Application No. UC 74 | Application published in METTLER TOLEDO Thermal Analysis UserCom 7}