Instrumental Limitations upon the Measurement of Temperature and Rate of Energy Production by Differential Scanning Calorimetry

Abstract

Instrumental time constants for rate of energy production response, temperature-programming response and temperature-averaging network response, time constants for a wide variety of conditions for interfacial conductivity between the sample and the calorimeter cup, and for the thermal conductivity of the sample are catalogued for the differential scanning calorimeter. Assessment of the effects of these factors upon the net rate of power production sensitivity and the temperature calibration results in the establishment of limits of precision in the measurement of temperature, specific heat and heats and rates of enthalpy change during chemical and physical transformations. The vulnerability of these calibrations to instrumental readjustment and variation in experimental techniques is also quantitatively evaluated.

Commercial instruments are identified in this paper to specify experimental procedure. This does not imply endorsement by the National Bureau of Standards or that they are necessarily the best available for the purpose.