Mikhal O. The development of the theory and practical implementation of immittans methods of convertation for primary thermo- and conductometric measurement.

Object of research: processes of measuring transformation in precision immitance thermo- and conduc-tometric devices. The purpose of the work: development of the theory of measuring the immitance of conductors of the first or the second kind in the direction of developing new models of sensors and principles of constructing measuring circles invariant to the main destabilizing factors, and creating on their basis precision instruments and systems for thermoconductivity. Research methods are based on numerical methods for calculating field problems, analytical methods using the theory of functions of a complex variable, conformal transformations, the theory of radio engineering circles and signals, and the theoretical foundations of information and measuring technology. Theoretical and practical results and novelty: a complex scientific and applied problem of the further development of the theory of measuring the immitance of conductors of the first or the second kind and the creation of precision in-struments and systems for thermo- and conductivity with metrological characteristics that meet the technical requirements of measuring instruments for national standards is solved. The mathematical models for calculating the errors of measuring the active component of the impedance of conductors of the 1st and 2nd kind are developed. We have developed the principles of constructing measurable cir-cles invariant to the non-informative parameters of the primary cells. New methods of determination of additive error and nonlinearity are developed. Subject and degree of implementation: The main results of the work are implemented: as a measuring system in the state standard of the unit of electrolytic conductivity, Ukrmetrteststandard, Kyiv; as a thermometric bridge CA300 in the state standard of the unit of degree Kelvin, NSC "Institute of Metrology", Kharkiv; as a means of measuring the tempera-ture «Delta R» in the state standard of the unit of combustion energy, NSC «Institute of Metrology», Kharkiv. Efficiency of implementation: it’s ensuring Ukraine's independence in the field of reproduc-tion, storage and transmission to working means of measuring physical quantities - electrolytic con-ductivity and temperature. Scope of application: National metrology institutes, regional centers of standardization, metrology, certification.