A radiation thermometer measures irradiation reaching its sensor and is calibrated to indicate the temperature of a blackbody that produces the same flux. A steel billet having a diffuse, gray surface of emissivity 0.8 is heated in a furnace whose walls are at \(1500 \mathrm{~K}\). A radiation thermometer views the billet through a small hole in the furnace. Estimate the actual temperature of the billet when the radiation thermometer indicates \(1160 \mathrm{~K}\). Assume the thermometer is sensitive to total irradiation.