Wavelength and intensity standard for spectrometers

摘要

The wave length- and intensity standard for calibrating and testing measurement heads in spectrometers, which are usable primarily in the near infrared region (NIR) of the spectrum, comprises a purely plastic plate, a plastic plate mixed with titanium oxide, a holder (1) and a plate body (2) arranged in the holder. The distance (A) between the two plastic plates is dimensioned in such a way that there is no interference between them. The plate body is made of transparent plastic to carry out transmission measurements. The surfaces of the plate body are not coated. The wave length- and intensity standard for calibrating and testing measurement heads in spectrometers, which are usable primarily in the near infrared region (NIR) of the spectrum, comprises a purely plastic plate, a plastic plate mixed with titanium oxide, a holder (1) and a plate body (2) arranged in the holder. The distance (A) between the two plastic plates is dimensioned in such a way that there is no interference between them. The plate body is made of transparent plastic to carry out transmission measurements. The surfaces of the plate body are not coated. The holder is closed outwardly by a cover plate (4) of tempered glass or by a sapphire disk. The plate body is made of transparent plastic with high strength and dimensional stability over a large temperature range. The plastic has distinct absorption bands throughout the entire NIR range and has a chemical structure and composition ensuring an extensive moisture barrier against water absorption and water release in a reliable and stable manner over time. The plate body comprises an amorphous, transparent copolymer based on cyclic and/or linear olefins. The plate body is constructed as a transparent plate, one of whose surfaces is coated with a diffusely reflecting layer (3). The diffusely reflecting layer comprises a paint containing titanium dioxide. The plate body has a roughened surface that is coated with a well-reflecting metal. The roughened surface is coated with gold. One surface of the plate body is provided with a metal-coated microlens array. The plate body is connected to a reflecting metal plate, which is fixedly arranged at or which is arranged at a distance from, the surface of the plate body that is roughened or that is provided with a microlens array. The plate body has two oppositely located smooth, transparent surfaces in which a plate which is roughened or coated with titanium oxide is provided. The roughened surface or coated surface of the plate fixedly contacts or is arranged at a distance from one of the smooth surfaces of the plate body. The plate body is made of a plastic with an admixture of 3% of titanium oxide.