An application of the emissive layer technique to temperature measurement by infrared optical pyrometer

Abstract

To achieve accurate low temperature measurement of a material under shock-loading, we performe a series of experiments of shocked Pb and Cu targets partially released thanks to the use of a LiF anvil. In order to reduce uncertainties of the true interface temperature due to the lack of knowledge of emissivity, a method consists in artificially increasing the dynamic emissivity of the material up to an apparent value of approximately 0.85 by the use of an emissive layer. The detected radiance is then amplified and the range of dynamic emissivity is restricted. Promising results at material/LiF interface at about 8 GPa obtained with an emissive layer of ReSi 2 indicate that the mechanical, thermal and optical properties of this layer can be characterized and the temperature of the material can be deduced. This paper examines different parameters (nature of the material, layer thickness) potentially influencing the measured radiances at this complex interface. © 2012 American Institute of Physics.