Patent ID: 7177025
Filing Date: 2007-02-13
Classification: G01N

Abstract:
1. Apparatus for measuring specular reflectance of a sample comprising: a sample holder, a light source for transmitting a beam of light at a predetermined angle of incidence onto a surface of a sample when held by the sample holder, the light source and the sample holder being mounted for relative movement to vary said angle of incidence; and a detector for detecting light of said beam which is specularly reflected from said surface of the sample, the detector and the sample holder also being mounted for relative movement, wherein the light source, the detector and the sample holder are correspondingly relatively positionable for a specularly reflected component of a transmitted light beam to be detected for different angles of incidence of the light beam and wherein corresponding relative positions of the light source, the sample surface and the detector are constrained such that said detector is located by said constraint to detect said specularly reflected component of said light beam at an angle of reflection, which is equal to the angle of incidence of the light beam on the sample surface, and wherein the detector for movement along an arc about said axis and the sample holder and the detector are operatively associated such that movement of the sample holder through an angle automatically rotates the detector through twice said angle.