A method being used to measure the erosive wear of metals at different temperatures and under controlled environmental conditions is described. A commercial apparatus has been modified that can be used for tests at 500°C and above and over a wide range of particle types, sizes, velocities, and concentrations. Test results from several iron and nickel base alloys are presented. Particular interest has been placed in the role of the oxide scale, in the particle velocity dependence and the impingement angle dependence of erosion rates, as well as the effect of varying particle concentration in the stream. Reproducibility among the tests of about 10 percent can be realized if care is exercised with regard to several important experimental parameters.