Thermomigration ratio measuring method, coefficient of thermal conductivity measuring method and the thermomigration ratio measurement equipment null by interchange

摘要

PURPOSE:To make it possible to measure material whose thermal diffusivity is small precisely and to make it possible to perform measurement including temperature dependency with a small-scale apparatus by making a current flow through a conductive thin film which is formed on a sample plate to be measured as an AC heat source. CONSTITUTION:A conductive thin film 2 is formed on at least one surface of a thin sample plate to be measured 1. A current is made to flow through the thin film 2. Thus an AC heat source which is heated with Joule's heat is provided. An AC which is modulated by a specified modulating frequency is made to flow through the AC heat source of the sample plate to be measured 1, and the AC heating is performed. The response curve corresponding to the AC heating is generated on the other surface facing the sample plate to be measured 1, and the phase of the response curve is measured. Thus the thermal diffusivity of the sample plate to be measured in the direction of the thickness is computed. The sample plate to be measured 1 is made of a material that is hard to be conducted and can be formed in the shapes of a film, a sheet or a plate, e.g. high-molecular compounds such as phenol, urea, melamine and the like. The conductive thin film 2 is made of material whose resistance value is changed, e.g. gold, silver, platinum and the like.