A new method for the absolute measurement of reflectivity

P. M. D. Bradshaw, R. Phillips, R. A. Smith
1966 Mineralogical Magazine and Journal of the Mineralogical Society  
The theory of a new method for the determination of reflectivity at truly normal incidence is described. A parallel light beam falls on the specimen after passing through a glass cube with semi-silvered diagonal mounted at the centre of an optical goniometer. The various reflected beams are measured by a photomultiplier fixed to the telescope of the goniometer. Experiment has proved the validity of the method and the spectral reflectivity of pyrite in air and in oil has been investigated.
doi:10.1180/minmag.1966.035.274.07 fatcat:sfjvy4jvu5fvbmwgmo5x5jzuia