Analytical Spectral Devices LabSpec 4 
            https://www.malvernpanalytical.com/en/products/product-range/asd-range/labspec-range/labspec-4-hi-res-analytical-instrument
            
            Reflectance spectra from 350 to 2500 nm (0.35 to 2.5 um) were measured at ambient temperature and pressure 
            relative to a calibrated Spectralon 99% diffuse reflectance standard with an Analytical Spectral Devices 
            LabSpec 4 Hi-Res spectrometer (ASD) at a viewing geometry of i=30°, e=0°. These spectra were corrected for the 
            absorption features of Spectralon. An in-house quartz-tungsten halogen light source was used to provided incident 
            light that was collimated to less than 1.5° divergence with a cold color temperature that provides sufficient 
            signal-to-noise ratio over the three sensors of the ASD instrument, with flux sufficiently low to not induce 
            observable emittance on very dark samples in the wavelength range under study. Five hundred scans of reflectance 
            spectra were collected for each sample, and 500 scans of dark current were subtracted from sample and standard 
            reflectance spectra.