Baba Ahmed, N.Benmoussat, A.Benouaz, T.2020-10-082020-10-082010-01-01Articale in Journal of fundamental and Applied Sciences Vol. 02 N. 011112-9867http://dspace.univ-eloued.dz/handle/123456789/7110Articale in Journal of fundamental and Applied Sciences Vol. 02 N. 01We propose a direct method of measurement of the total emissivity of opaque samples on a range of temperature around the ambient one. The method rests on the modulation of the temperature of the sample and the infra-red signal processing resulting from the surface of the sample we model the total emissivity obtained in experiments according to the temperature to establish linear correlations. This leads us to apply the method of optimal linearization associated the finite element method with the nonlinear problem of transfer of heat if thermal conductivity, the specific heat and the emissivity of studied material depend on the temperature. We obtain a good agreement between the resolution of the nonlinear equation of heat and the results obtained by the experimentation.frEmissivity, Température, optimal Linearisation, finite elements.Article