DSC Baseline Subtraction

Baseline flatness and reproducibility are key factors that determine DSC sensitivity.  There are two approaches that could be used to obtain good DSC baselines.  One approach recommended by certain vendors is to run a baseline under the same experimental conditions as the sample material and subtract that baseline from the sample results.  This questionable, and inefficient practice is an example of BAD SCIENCE. It requires roughly double the experimental time, and is based on the dangerous assumption that the instrument's baseline is absolutely reproducible. If the latter assumption is not true, it is possible to subtract out real thermal events. 

The preferred approach is to design the DSC cell so that the factors that contribute to baseline drift and curvature are minimized and eliminated in the heat flow measurement. TA Instruments patented Tzero design used in the Q Series DSC's is based on this approach and is "good science".  Baselines obtained from the Q Series DSC's are typically 10X better than other commercial units. Flat and reproducible over a wide range of temperatures (see Figures 1 & 2), and heating rates, the baselines obtained on a TA Instruments Q Series DSC with Tzero technology ensure accurate and reproducible thermal analysis measurements.