Analytical Spectral Devices FieldSpec 3 
            https://www.malvernpanalytical.com/en/products/product-range/asd-range/fieldspec-range 
            {website only has info for upgraded FieldSpec 4}
            
            Manual for FieldSpec 3 available at
            http://www.geo-informatie.nl/courses/grs60312/material2017/manuals/600540-JFieldSpec3UserManual.pdf
            
            The 0.35-2.5 um range was acquired at ambient room temperature and pressure with an Analytical Spectral Devices 
            FieldSpec 3 with fiber optic cable bundle. Spectral resolution was 3 nm FWHM in the 0.35-1.0 um range and 10 nm 
            FWHM resolution from 1.0-2.5 um. Geometry (biconical) of the measurements was an incidence of 0º and emission 
            angle of 30º, for a phase angle of 30º. Illumination was provided by a bare quartz halogen full spectrum bulb 
            40 cm above the sample. Measurements were taken relative to a flat Spectralon standard that was positioned at 
            the same height as the sample.