Thermal Conductivity Measurement of Solid Materials by Thermistor Direct Heating Method

Background. This work addresses the development of an experimental device and increasing the accuracy of determining the thermal conductivity of solid materials by thermistor direct heating method. Objective. The aim of the paper is to create the installation, conduct experimental studies to determine the value of the thermal conductivity of solid materials by thermistor direct heating method and to research destabilizing factors that affect the measurement error, and to suggest ways to increase the accuracy of measurements. Methods. Experimental device has been created, which work is based on the direct heating method of the thermistor and necessary researches have been carried out. The results of the measurement are given by setting the thermal conductivity coefficients of various materials, which make it possible to expand the scope of the method. Results. Rational operating modes and design of probes for measuring the thermal conductivity of solid materials depending on their TPC are proposed and justified. Ways to reduce the measurement error by thermistor direct heating method are presented. Investigation of destabilizing factors influencing the measurement error made it possible to determine means of reducing their influence on the results of determining the thermal conductivity of solid materials and to suggest ways to increase the accuracy of measurements. Conclusions.The experimental device has been tested experimentally and implemented in the research and production activities of “VIRCOM” and in the educational process of the Department of Instrumentation Design and Engineering of the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”.