A modified dual-slope method for heat capacity measurements of condensablegases

A high resolution nonadiabatic method for measuring the heat capacity (C-P) of bulk samples of condensable gases in the range of 7.5-70 K is described . In this method C-P is evaluated by directly comparing the heating and coo ling rates of the sample temperature for two algebraically independent heat pulse sequences without explicit use of the thermal conductance between sa mple and thermal bath. A fully automated calorimeter for rapid measurement of C-P of molecular solids utilizing this technique is presented. The techn ique along with the automated calorimeter with a provision to apply externa l electric and magnetic fields is particularly useful for the study of cont inuous phase transitions in molecular solids as well as field induced chang es in the heat capacity. (C) 2000 American Institute of Physics. [S0034-674 8(00)02710-6].