  Thermoelectric power sensors used as power transfer standards are promising
devices for further enhancements of the microcalorimetric technique in the high
frequency field. A coaxial microcalorimeter has been studied, based on
thermoelectric power sensors, at Istituto Nazionale di Ricerca Metrologica
(INRIM). In the literature, several models have been proposed, considering
different calibration processes and error sources. Hereby we analyze these
models in terms of total uncertainty for the 3.5 mm coaxial line case between
10 MHz and 26.5 GHz. Merits and limits of the models are highlighted.
