MTDSC Calibration Dependence of the Instrumental Response Upon Experimental Conditions

The heat capacity calibration ‘constants’ of a commercial MTDSC system (TA 3100) were determined in a variety of experimental conditions. For a given modulation frequency, the calibration constants are the same within a few percents for different temperatures, and over a wide range of modulation amplitudes and scan rates. This variation decreases below 1% if hidden instrumental constraints are taken into account, which are related with the capability of the control system to achieve the desired temperature program. On the other hand, the calibration constant changes substantially with the period, and takes anomalously high values for the short modulation periods (20+40 s). Rules to optimize the accuracy of the system are given. This revised version was published online in August 2006 with corrections to the Cover Date.