Abstract The present work describes a method for the temperature measurement in furnaces or test rigs for the range 750 – 1000°C by means of the selective oxidation of nickel in palladium-gold-nickel alloys in a constant oxygen atmosphere (pO2 = 2.1 · 104 Pa). For this method, extensive aging tests using alloys of different compositions (PdAu x Ni2, x = 0; 10; 15; 20; 30 wt. %) were performed and the alloy-dependent material constants ln(A) and B of the Arrhenius equation were determined. These values allowed for the spatially resolved evaluation of the temperature load by means of a metallographic analysis of the oxidation depth. It is furthermore shown that the oxygen diffusion rate in PdAuxNi2 as well as the activation energy needed decrease with increasing gold content x, while the lattice constant a increases. In addition to that, a geometric derivation for the determination of the layer thickness is presented aiming at simplifying the preparation of the wire-shaped samples.