Development of an Inorganic Temperature Sensitive Paint for High Temperature Environments

Abstract

Temperature sensitive paint (TSP) is a measurement technique based on luminescent molecules which exhibit property change (i.e. increasing, decreasing emission intensity or luminescence lifetime) due to changing local temperature. It is used to measure surface temperature distributions and heat flow fields for specific temperature ranges with high spatial resolution. In recent years, much research has been carried out on organic luminophores for cryogenic and ambient temperatures and, more recently, on inorganic phosphor materials for a temperature range from 30 up to 230 °C at the German Aerospace Center in Göttingen. In this work, inorganic phosphor materials are investigated which exceed the upper temperature limit of organic luminophores. These include ((Sr1-xCax)AlSiN3:Eu2+, YVO4:Dy3+, Y(V,P)O4Eu3+, YAG:Eu3+, YAG:Dy3+ and LuAG:Dy3+ covering individual temperature ranges between 300 and 1300 °C. Excitation and emission spectra, reflectance spectra, particle size distributions, external quantum efficiencies, thermal quenching curves and powder X-ray diffraction patterns were measured to characterize the phosphors which proved to be suitable towards the development of a high temperature TSP.