@book{5727bff6fa914e26b1eb44a25d926f12,
title = "A transient symmetrical method for the measurement of temperature dependent thermal diffusivity",
abstract = "Determination of temperature dependent thermal diffusivities using a transient symmetrical method was studied. The thermal diffusivity is determined from the temperature profile in a specimen constructed of thin slabs and heated symmetrically from both sides. The thermal diffusivity is determined as the ratio of the time derivate and the second spatial derivate at the position of the extremum of temperature. A numerical method was developed to calculate the thermal diffusivity as a function of time including the confidence interval of the diffusivity. The numerical methods were validated by using numerically calculated temperature profiles for a material with known thermal diffusivity. Preliminary tests were conducted to investigate the practical applicability of the method. The method proved to work for an inert material when no changes of geometry of the sample occurred. If reactions, convection, or substantial thermal expansions causing gaps inside the specimen occur, the results will not be well-defined.",
keywords = "fire safety, temperature, measurement, thermal diffusivity, thermophysical properties, heat transfer, calculations, utilization, experimentations, numerical analysis, test methods, transiet analysis, time, mineral wool, calcium silicates, insulating boards, geometry",
author = "Matti Kokkala and Djebar Baroudi",
year = "1993",
language = "English",
isbn = "951-38-4345-9",
series = "VTT Tiedotteita - Meddelanden - Research Notes",
publisher = "VTT Technical Research Centre of Finland",
number = "1452",
address = "Finland",
}