Determination of the effective emissivity distribution of a heated specimen using tandem acousto-optical tunable filter

Abstract

Abstract We present the first experimental demonstration of a new imaging system for in-situ measurement the two-dimensional distribution of the effective emissivity and temperature of a heated specimen. In this work, we use the model of a gray body, assuming that the emissivity is constant over the entire wavelength range from 600 to 800 nm. Data acquisition was done using the laser heating (LH) system developed at the STC UI RAS. The LH system allows us to reach extremely high temperatures up to 6000 K at high pressures. The main component of the system is an imaging tandem acousto-optical tunable filter synchronized with a video camera. The maximal error of the emissivity measurement of the tungsten sample was found to be 13%, whereas the maximal error of the temperature measurements did not exceed 2%. An influence of different factors on the error of the emissivity determination is also discussed.