Thermal conductivity and specific heat measuring method and device null

摘要

PURPOSE: To accurately decide the specific heat and heat conductivity of a fluid by using only one detector by giving a transient temperature change and an energy input of such a level and a length that substantially generate a stable-state temperature to a sensor means. CONSTITUTION: An instrument for measuring heat conductivity and specific heat of a fluid is constituted so that the instrument can generate a temperature pulse in one or more heating elements closely arranged in a fluid to be measured. The hourly changing temperature response of a heater to the pulse changes correspondingly to the characteristic values, such as the heat conductivity (k) and specific heat cp of the fluid. When the fluid flows in the state of a relatively stable sample flow, the hourly changing responses of one or more heat-sensitive sensors coupled with heat generating bodies through the fluid change. The length of the thermal pulse from a supply source must be such a degree that the heat generating bodies reach stable states only during a short period. The pulse causes both stable states and transient states in the sensors. Therefore, the heat conductivity (k) is decided from the flat section of a temperature graph indicating the stable states and the specific heat cp is obtained from the conductivity (k) and the rate of temperature change.