Abstract: A method for conducting a differential thermal analysis, in which a sample disposed in a temperable sample space is tempered according to an essentially linear temperature program extending from a start temperature to an end temperature, such that, from the result of a measurement of the sample temperature conducted during tempering at a number of measurement time points, a DTA signal is calculated as the difference between a measured sample temperature and a reference temperature calculated according to a temperature curve model. According to the invention, for every measurement time point, the relevant reference temperature is calculated by the following steps: (a) establish a time interval containing the relevant measurement time point; (b) calculate a non-linear adjustment function for the measured sample temperature curve in the time interval; and (c) calculate the reference temperature as a value of the adjustment function for the measurement time point.

Abstract: A device for the photothermic investigation of a sample, with an excitation source for generating an electromagnetic excitation beam directed onto an excitation side of the sample, a detector for detecting thermal radiation emitted by a detection side of the sample, and a temperature-controllable sample chamber with a sample holder accommodated therein for the arrangement and temperature control of the sample. According to the invention, provision is made such that an adjustable detection lens system is provided between the sample holder and the detector, the detection lens system being adjustable in order to adjust a desired field of vision of the detector on the sample surface.