Nano-watt stabilized DSC and ITS applications

Summary

A high sensitivity and high resolution DSC working between 220 and 400 K with a baseline stability of &plusmn;3 nW for many hours, with a low noise of nV order, with a quick response time of 2 s and with the temperature resolution of 0.1 mK, capable of measuring in the both direction of heating and cooling has been designed and constructed. The stability of the baseline was achieved by the use of a high sensitive temperature sensor, a precise temperature control of &plusmn;0.1 mK, a semi-adiabatic control, the damping devices to decrease the temperature fluctuation at the sample cell and the devices to decrease noises on the lead wires. The specific heat capacity of a single crystalline alumina was measured with an inaccuracy of 1&percnt; by the use of the DSC. Very fine structures of phase transitions were observed at a cooling rate of 5 &micro;K s<Superscript>-1</Superscript> in the measurement of C<Subscript>22</Subscript>H<Subscript>46</Subscript> by application of the high sensitivity DSC. The measurement for very small samples of &micro;g order has become possible using the high sensitivity DSC and the application for the melting transition of C<Subscript>15</Subscript>H<Subscript>31</Subscript>COOH and C<Subscript>32</Subscript>H<Subscript>66</Subscript> was presented.