AN AUTOMATED ADIABATIC CALORIMETER FOR USE FROM 80 TO 600 K——HEAT CAPACITIES OF α-ALUMINA

Abstract

The construction of an automated adiabatic calorimeter for use from 80 to 600 K is reported. The main feature of the calorimoter is to mount three radiation shields in the cryostat for advancing the working tomperature. The molar heat capacity of α-Al_2O_3 has been measured in order to assess the reliability of the calorimeter. Deviations of the experimental heat capacities of α-Al_2O_3 from the smoothed curve are within ±0.3% except for a few experimental points. Our smoothed results agree with those of tho National Bureau of Standards. USA, within ±0.3% over the entire working temperature range.