Hemispherical Reflectance of Laser Gold

The first test of the coating was to determine the solar absorptance and the directional hemispherical spectral reflectance from 250nm-2800nm.  AZ Technology specifically designed and built the Laboratory Portable SpectroReflectometer (LPSR-200IR) to perform such measurements.  The LPSR-200IR measures the directional hemispherical spectral reflectance of the sample at 100 wavelengths in less than two minutes from 250nm-2800nm and from this data calculates the solar absorptance. 

A total of ten measurements using the LPSR-200IR were taken of the various surfaces of each part to determine the hemispherical reflectance and solar absorptance.  The measurements showed that the optical properties of the coating were fairly uniform from each surface of earch part.  The solar absorptance varied from 0.1853 to 0.1890 (averaged 0.1877).  The spectral reflectance at each of the 100 wavelengths for each of the ten runs was averaged to produce the graph shown.  The tabular data is also included. 

Hemispherical Reflectance of Laser Gold
Total Hemispherical Reflectance vs. Wavelength for Laser Gold