TIME LAG APPROACH FOR MEASURING THERMAL CONDUCTIVITY AND SPECIFIC HEAT

摘要

A method and apparatus for providing a more direct approach to determine thethermal conductivity, thermal diffusivity and specificheat of a fluid of interest, independently of the amplitude of the sensoroutput. This is preferably accomplished by measuring one or morevariable phase or time lags between selected input and output AC signals, anddirectly deriving the thermal conductivity, thermal diffusivityand specific heat therefrom. Such derivation is therefore less dependent thanamplitude-based sensors on occasional or unpredictable driftin sensor resistive elements.