Abstract: TC-Ⅱ heat conductivity measuring apparatus can be used to measure the heat transfer coefficient of material based on the stability method. However，experimental teaching activity shows that students have difficulty in determining the steady state using the TC-Ⅱ measuring apparatus due to long unsteady transition time，and the thermocouple temperature measurement needs cold end temperature compensation and the linear approximation between thermoelectric potential and the temperature. Therefore，the accuracy and repeatability of the students’measurement results are affected by the above issues. This paper proposes a temperature measurement and control improved circuit with a simple structure. It can effectively improve the accuracy and reproducibility of thermal conductivity measurement.

Key words: heat transfer coefficient, stability measurement, temperature measurement and control, improved design