Abstract: Disclosed is an integrating sphere for measuring the diffuse reflectivity of material samples in the infrared. The sphere is disposed in an airtight vacuum chamber under an atmosphere that does not absorb in the infrared. The sphere has two positions at which a sample may be mounted, one on a rod at the sphere's center, another on the sphere's wall, each mounting position corresponding to two different modes of testing samples. The rod acts as a mounting pedestal for a center mounted sample, and is rotatably mounted about its elongate vertical axis so that the sample can rotate with the rod in a horizontal plane. The rod penetrates the sphere and the chamber, and terminates in a knob or handle by which the rod can be rotated to position the sample at a preselected angle. Adjacent to the position for wall mounting, there is a sample heater. This configuration allows one to measure diffuse reflectance of a sample as a function of incidence angle and temperature.

Abstract: A novel light integrating sphere of a preferably appropriately sintered fluorinated aliphatic long chain addition solid polymer block, hollowed to provide an internal integral diffuse reflectance spherical surface.

Abstract: This invention involves a novel egg-shaped hollow dual-compound conical light-ray concentrator with mirror-like inner walls (preferably tandem substantially inverted paraboloidal and ellipsoidal conical sections) for receiving light through one aperture end, as from an integrating sphere, and concentrating and collecting the rays within said walls and directing them to a detector at an opposite aperture end. This construction attains both high collection efficiency and hemispherical angular response.