| 摘要 |
PURPOSE:To achieve a shortened measuring time and a simplified construction, by comparing the reflected light from an object to be measured with the reflected light from a reference reflection plate with the known reflectance to calculate the emissivity. CONSTITUTION:This measuring apparatus is made up of an optical means having an light source, a spectroscopic element 4, an photoelectric element 5, a heat supply means 6, a thermometer 7, a lock-in amplifier 9 and a microcomputer which has a spectroscopic wavelength selection means 13, a temperature control means 14 and an emissivity computing means 15 and the like. Then, first, the reflected light R0 from a reference reflection plate 16 having a reflectance rho0(lambda) at the wavelength lambda at the normal temperature is measured to determine the reflected light R*(lambda) at the reflectance of 100%. Then, the reflectance rho(lambda, T) is determined from the reflected light R(lambda, T) of an object 10 to be measured at the temperature T to calculate the emissivity epsilon(lambda, T) using the expression of the reflectance rho(lambda, T) and the emissivity epsilon(lambda, T), epsilon(lambda, T)=1-rho(lambda, T). Thus the spectroscopic emissivity can be determined in a short time without requiring a black body furnace. |
