Infrared spectral emissivity characterization facility at NIST

A new facility for the measurement of spectral emittance (emissivity) of materials that employs a set of blackbody sources is being built at NIST. This facility has also been used to investigate the capabilities of Fourier transform (FT) spectrometers to characterize the spectral emissivity of blackbody sources. The facility covers the spectral range of 1 μm to 20 μm and temperatures from 600 K to 1400 K. The principle of operation involves the spectral comparison of an unknown source with a group of variable temperature and fixed point reference sources by means of the FT spectrometer and filter radiometers. Sample surface temperature is measured by non-contact method using a sphere reflectometer. The current reflectometer setup allows measurements of opaque samples, but it is planned to include semitransparent materials at a later stage.