Differential Scanning Calorimetry (DSC)
Differential Scanning Calorimetry (DSC)
Differential Scanning Calorimetry (DSC)
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<strong>DSC</strong>: Heat Flux Principle<br />
The differential temperature ( ∆ T)<br />
between the sample and<br />
reference is converted to differential heat flow in a way that<br />
is analogous to current flow in Ohms Law.<br />
I = E/R where: I = current<br />
E = voltage (potential)<br />
R = electrical resistance<br />
∆<br />
Heat Flow =<br />
T k 1 k 2 where:<br />
R<br />
∆T<br />
= temperature difference (potential)<br />
R = thermal resistance of constantan disk<br />
k 1 = factory-set calibration value<br />
k 2 = user-set calibration value<br />
<strong>DSC</strong>: How Heat Flux is Measured<br />
• Heat flow through the chromel wafer causes a<br />
temperature difference ∆T. The temperature<br />
difference is measured as the voltage difference ∆U<br />
between the sample and reference constantan/chromel<br />
junctions. The voltage is adjusted for thermocouple<br />
response S and is proportional to heat flow.<br />
∆T = ∆U / S ∆T in °C<br />
∆U in µV<br />
S in µV/°C
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