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Information × Registration Number 0225U001232, (0120U105508) , R & D reports Title Research of thermal bridge measuring schemes for measuring thermophysical characteristics of materials popup.stage_title Дослідження теплових мостових вимірювальних схем для вимірювання теплофізичних характеристик матеріалів Head Fedynets Vasyl O., Доктор технічних наук Registration Date 28-01-2025 Organization Lviv Polytechnic National University popup.description1 Research of thermal bridge measuring schemes and development on their basis of devices for measurement of thermophysical characteristics of materials popup.description2 The principles of construction of thermal measurement circuits (TMC) for solving the problems of measuring the thermal conductivity of plates and sheet materials are analyzed. Based on the theory of thermal circuits, mathematical models of a balanced bridge TMC are developed. New designs of variable thermal resistances are considered, and their significance for balanced bridge TMC is shown. The functional and metrological characteristics of the measuring transducer of thermal conductivity of plates and sheet materials, built on the basis of a balanced bridge TMC, are studied. The sensitivity of the developed bridge TMC is analyzed. A methodology for calculating the design parameters of the thermal conductivity measuring transducer according to the criterion of optimal sensitivity in a given measurement range is presented, as well as determining the ratios between the thermal resistances of the TMC elements that ensure the invariance of the output signal of this scheme to non-informative parameters. The results of experimental studies confirming the condition of invariance of the output signal of the TMC to the specified non-informative parameters are presented. Experimental studies of the measuring converter of thermal conductivity of plates and sheet materials in the range from 40 to 400 W/( м∙К), which implements a bridge TMC with balancing of heat fluxes passing through the test and standard samples, have been carried out. The method of calibration of the thermal conductivity measuring transducer using standard thermal conductivity materials is considered. Product Description popup.authors Vasylkivskyi Ihor S. Romaniuk Danylo V. popup.nrat_date 2025-01-28 Close