ABSTRACT
A new dynamic technique for the determination of the thermal conductivity of electrical conductors is being implemented at the CNR Istituto di Metrologia “G. Colonnetti” (IMGC, Italy). A tubular specimen undergoes a subsecond Joule heating and in the following free cooling period the temperature profiles are measured via microsecond scanning pyrometry. Thermal conductivity is reconstructed in form of polynomial approximation by solving the associated nonlinear inverse conductive problem with the use of the Kalman filter. This stochastic technique provides a way to consider the various noises and disturbances affecting the measured signals. Some simulated and preliminary experimental results on niobium are presented and discussed. From a single cooling experiment the above procedure is able to reconstruct the temperature dependent thermal conductivity in the range 1300–2300 K.
