Abstract: An optical sensing instrument for detecting specular and/or non-specular reflections of light from a surface under test has a sensor head with a plane face having a semi-circular recess in which are housed a plurality of light sources and a plurality of photodetectors each having an associated lens, the optical axis of which passes through the center of curvature of the semi-circular recess. The photodetectors and the light sources are positioned such that respective source/detector pairs are located on optical axes which form mirror angles with respect to the axis of symmetry of the sensing head. Means are provided for simultaneously energizing one or more selected light sources and one or more of the photodetectors.

Abstract: An optical diffractometer is disclosed in which there is provided a television camera system for displaying light patterns derived from the image plane or the transform plane of the diffractometer. The camera system includes a modulating network for providing a pseudo three dimensional display by mixing signals from the X ramp and Y ramp generators together and by mixing the signal from the Y ramp generator with a signal representative of the television camera beam current. The mixed signals are applied to the X and Y plates of a cathode ray tube to provide a display of the signals.