VALIDATION OF A PYROMETER FOR SPACE APPLI CATIONS

The subject of this paper is the accurate surface temperature measurem ent of ceramic materials for thermal protection systems of reentry veh icles inside an arc-heated wind tunnel. It will be shown that it is po ssible to make these accurate measurements with the help of a photoele ctric spectral pyrometer, if the parameters for the determination of t he temperature, e.g. the emittance, are set as accurately as required. The disturbing plasma radiation and other undesired effects can be ci rcumvented when the temperature measurement is carried out with a newl y developed miniaturized spectral pyrometer located inside the protect ed part of the material probe. The corrections of these pyrometrically measured surface temperatures are essential and must be modelled and ascertained. The design, test and qualification of the new temperature measuring device are discussed.