Measurement for hemispherical emissivity of polished pure gold

The measurement for hemispherical emissivity of polished pure gold at 60-300°C is reported. The influence of ambient temperature on the measuring value of the emissivity is discussed. Although the temperature difference between the cooling temperature and ambient temperature is quite large, the error of the measuring value of the emissivity is small. Therefore the emissivity can be measured by using tap water or a slightly cooled medium instead of liquid nitrogen coolant.