Development of an Adiabatic Ultramicrocalorimeter

To measure heat capacities of a very small amount of samples (about 10 – 100 mg) by an adiabatic microcalorimeter, ultramicro cells have been developed. These cells consist mainly of DSC pan, copper plate, and Apiezon N grease. Using these cells, heat capacities of benzoic acid (NIST, SRM 39i), synthetic sapphire (NIST, SRM 720), and Milli-Q water were measured. The deviations of the experimental heat capacities from the literature data were about 1 %.

(by S. Arai & Y. Miyazaki)

Fig. 1. Structure of an ultramicro cell.

Fig. 2. Heat capacities of empty cells.

Fig. 3. Molar heat capacities of benzoic acid (NIST, SRM 39i) and synthetic sapphire (NIST, SRM 720).

Fig. 4. Molar heat capacity of Milli-Q water.