An adiabatic low-temperature calorimeter for small samples

A low-temperature adiabatic microcalorimeter for heat capacity determination was developed. The calorimeter is of the twin type, consisting of a sample cell and thermometric copper block. The temperature of the cell is transferred to the block by a fine thermocouple and a controlling system, and the temperature of the block is measured by standard thermometry. This reduces heat transfer through thermometer leads and thus avoids self-heating due to thermometric current. Heat capacities of two sample cells, one is 0.6 cm 3 and the other 1.2 cm 3 in the internal volumes, were measured in the temperature range between 13 and 300K with discontinuous heating mode. Accuracy of the calorimeter was tested by a US calorimetry conference standard benzoic acid crystal. The estimated inaccuracy is 1% at 20K, 0.1% at 70K and 0.3% above 170K.