The dissertation is devoted to the development of theoretical grounds and principles of construction of a new class of temperature fixed points: with use of metal melts of eutectic concentration as working substance. The reasons for the instability of reproduction of melting-crystallization of phase transitions temperature are analysed. It is established, that base sources of instability of reproduction of temperature and non-uniqueness of ITS-90 metal fixed points are ambiguity of impurity concentration and nature definition as well as lack of appropriate unified technologies of crystallization phase transitions realization individual for each working substance. On the basis of entropy-cluster analysis, as well as radiographic and viscosimetrics explorations it is shown, that eutectic melts preserve micrononhomogeneous structure within certain temperature interval after melting. It is theoretically finished and experimentally confirmed, that due to their correlation in cluster distribution the structure the structure of eutectic melts is sensitive to the imposing of physical fields. The methodology of estimation of the values of power influence on the melt of working substance with the purpose of forming fine-dispersed, even-grained, energetically-sated structure which provides the most isothermal plateau of melting is developed. The control of formation of an optimum level of uniformity and dispersiveness of crystalline structure of working substance during its crystallization is carried out with use of adapted method of acoustic emission (АЕ). During melting the developed method is used for defining the start and end of phase transition. With the application of radiographic, viscosimetric, calorimetric, metallographic, differential thermal and AE methods of analysis the precision composition of an eutecticum of In-Ga-Sn system the necessary level of melt overheating, parameters of its power treatment and conditions of crystallization, optimum for obtaining subsequent maximum isothermal plateau of melting is in vestigated as well as level of its long stability. The width of provided temperature interval of the plateau of melting does not exceed 0,008°C. Mobile fixed points using eutectic melts of In-Ga-Sn and In-Bi systems as working substance are developed and investigated. Realization of the melting plateau with parameters archived temperature stability x duration of a plateau registration with the corresponding temperature) is provided: (0,02°C x5 hour 10,58°C); (0,03°C x1 hour 72,73°C). The mobile fixed point with the use of thermoelectric stabilizing agent of furnance temperature and AE-complex of control of the necessary level of stabilizing power treatment of working substance is developed. Key words: temperature, measurement, thermometric property, temperature scale, gaugings, temperature fixed point, phase transition, thermophysical basis of structure stabilization, eutectic, melting, crystallization, structure, melts micrononhomogeneity, thermal analysis, radiography, viscosimetric, acoustical emission, calorimetric.
