Zc. Tan et al., AN ADIABATIC LOW-TEMPERATURE CALORIMETER FOR HEAT-CAPACITY MEASUREMENT OF SMALL SAMPLES, Journal of thermal analysis, 45(1-2), 1995, pp. 59-67
A small sample adiabatic calorimeter for measuring heat capacities in
the temperature range 60-350 K using the Nernst method has been constr
ucted. The sample cell of the calorimeter is 6 cm(3) in the internal v
olume, equipped with a miniature platinum thermometer and surrounded b
y two adiabatic shields. Two sets of 6-junction chromel-copel thermoco
uples were mounted between the cell and the shields to indicate the te
mperature differences between them. The adiabatic conditions of the ce
ll were automatically controlled by two sets of temperature controller
. A mechanical pump was used to pump out the vapour of liquid nitrogen
in the cryostat to solidify N-2 (1), and 60 K or even lower temperatu
re was obtained. The performance of this apparatus was evaluated by he
at capacity measurements on a-alumina. The deviations of experimental
results from a smoothed curve lie within +/-0.2%, while the inaccuracy
is within +/-0.5% compared with the recommended reference data in the
wole temperature range.