Construction and testing of a sublimation calorimetric system using a Calvet microcalorimeter

Abstract A sublimation calorimetric system has been constructed, in which a Calvet microcalorimeter and Knudsen-type sample containers are incorporated. Two kinds of sublimation apparatus with three kinds of sample containers have been designed. Two of the containers are furnished with a stopper, which can be placed or removed under vacuum from the outside of the apparatus. Thus, these containers are applicable to substances that are unstable in air. The latest version of the containers is applicable also to corrosive substances. The system has been tested with naphthalene and anthraquinone and found to enable us to determine sublimation enthalpies at temperatures from ambient to 450 K, for substances with saturated vapor pressures of 1 to 400 Pa, with satisfactory precision and accuracy.