Estimation of Transition temperature:
The precise determination of a transition temperature (e.g. M. P. and B.P.) up to a precision of ± 0.3oC over a huge range of heating rate. The temperature estimated for M.P. Tm or B.P. TB, were most frequent selected from the portion peak as display in Figure. Within this figure first a base line meeting low and high temperature sides of the peak is drawn where A is the intersection of extrapolated straight line portion of the low temperature side of the peak along with the base line. Additionally, point B is the inflection point of low temperature side of the peak and point C is the extrapolated peak, when D is the extrapolated return to the base line. Melting point Tm is measured through the using sample is closest to the temperature of point C for sample and temperature at B for reference. In exceptional cases it might closer to point D.
Figure: The different temperature of DTA curve.