Measurement of Specific Heat Functions by Differential Scanning Calorimetry

When a sample material is subjected to a linear temperature program, the heat flow rate into the sample i s proportional to its instantaneous specific heat. By recording this heat flow rate as a function of temperature, and comparing it with the heat flow rate into a standard material under the same conditions, the specific heat of the sample i s determined as a fundion of temperature. The method is illustrated by measurements on various samples in the temperature range 340" to 510" K., and agreement with literature specific heat values is demonstrated. The ultimate precision of the method is 0.370 or better, which approaches the precision of adiabatic calorimetry. However, measurements may be made with samples which are four orders of magnitude smaller, and program rates two orders of magnitude larger, than those typical of conventional calorimetry.