A sensitive adiabatic calorimeter for measurement of low-temperature specific heats

An adiabatic calorimeter has been designed and constructed which allows measurements of the absolute value of specific heat to be made on small quantities of material in the temperature range 20-300K. The exchange of heat between the calorimeter and its environment has been eliminated with the aid of three screens which were automatically controlled to have the same temperature as the calorimeter. The elimination of heat loss allowed the temperature of the calorimeter to be measured after a stabilization period had followed the heating of the calorimeter. The experimental results are shown to be reproducible and to reflect the sensitivity of the method.