Assessment of thermal conductivity of the building materials. 'Hot wire method': Fid-Bau Portal

Assessment of thermal conductivity of the building materials. 'Hot wire method'

Zach, J. / Stastnik, S.

Non-stationary measuring equipment means a progress in methods of simple, reliable and quick determination of heat conductivity of building materials. This paper describes a new method of building materials heat conductivity coefficient determination including all involved procedures and evaluates the advantages connected with the use of this method. The thermal conductivity coefficient is the most important heat technical property of building materials - it characterizes the ability of materials to conduct heat energy. Two groups of testing methods are used in practice for the measurement of heat conductivity as materials property: Stationary methods (hot plate method, cylinder method, sphere method). These methods are quite accurate but they are time-consuming (no possibility for measuring of materials with moisture content) and the application of these method is possible only in the case of samples with exactly determined dimensions and they are very demanding concerning sample preparation. Non-stationary methods - shock methods ('Hot Wire Method', 'Flash Method') utilizing secondary measuring instruments. The non-stationary methods for the determination of the heat conduction coefficient are utilized particularly in cases where an application of the slab method cannot be applied. The lower measurement reliability is compensated especially by the quick realization of the experiment. The experiment evaluation is quick and it can be algorithmized for on-line processing by a computer.