US Patent 9689746 Method and system of measuring surface temperature

Provided is a measuring method capable of accurately measuring the surface temperature of a surface to be measured, uninfluenced by the emissivity distribution of the surface to be measured. A surface to be measured having an emissivity distribution, a radiometer that measures a radiance distribution of the surface to be measured, and an auxiliary heat source installed in a specular reflection position from the radiometer with respect to the surface to be measured are prepared, radiances of two places having different emissivities of the surface to be measured are measured at two different auxiliary-heat-source temperatures, a reflectance ratio of the two places having the different emissivities is calculated on the basis of two measured radiances of the two places having the different emissivities, and temperature of the surface to be measured is obtained using reflectance ratio and measured radiances of the two places having different emissivities.