The variation of total normal emittance as a function of oxide thickness on a metal sub strate is investigated experimentally for Al-Al2O3 and Cu-CuO systems. The measurements are made using a comparative black-body technique. Over the range of aluminumoxide thicknesses investigated (1.2μ–86.4μ) the total normal emittance varies from 0.15–0.92 for a sample temperature of 96 deg C. With a copper-oxide thickness range from 1.2μ–5.6μ, the total normal emittance varies from 0.09–0.81 at 96 deg C. An analytical solution to the foregoing problem is formulated and the total normal emittance of the anodized aluminum samples is computed. Although the theoretical values are lower than the measured values, the effect of increasing oxide thickness on emittance is similar.
