The normal spectral emissivity of niobium strip specimen is measured using a new pulse-heating reflectometric technique. The hemispherical spectral reflectivity of the surface of a strip tangent to an integrating sphere is determined by a high-speed lock-in technique. At the same time, the radiance temperature of the strip is measured by the multi-wavelength high-speed pyrometer from approximately 1000 K to the melting point. Details of the measurement method and of the related calibration techniques are reported. Results of the normal spectral emissivity of niobium at 633, 753, 827, and 905 nm from room temperature to its melting point are presented. The accuracy of spectral emissivities is estimated better than 5%.
© 2006 Chinese Optics Letters
(000.6850) General : Thermodynamics
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.4570) Instrumentation, measurement, and metrology : Optical design of instruments
(120.6780) Instrumentation, measurement, and metrology : Temperature
(300.2140) Spectroscopy : Emission
Qingwei Wang, Peng Xiao, Jintao Yu, and Jingmin Dai, "Measuring normal spectral emissivities of niobium by a pulse-heating technique: 1000 K to the melting point," Chin. Opt. Lett. 4, 701-704 (2006)