Abstract: An apparatus for the calibration of optical measuring instruments with a carrier includes a calibration body having a glass body which has at least one scattering element, wherein the scattering element is completely surrounded by the glass body, and wherein a degree of transmission of the scattering element and of the glass body differ from one another.

Abstract: An apparatus for the calibration of optical measuring instruments with a carrier includes a calibration body having a glass body which has at least one scattering element, wherein the scattering element is completely surrounded by the glass body, and wherein a degree of transmission of the scattering element and of the glass body differ from one another.

Abstract: An apparatus for the calibration of optical measuring instruments with a carrier includes a calibration body having a glass body which has at least one scattering element, wherein the scattering element is completely surrounded by the glass body, and wherein a degree of transmission of the scattering element and of the glass body differ from one another.

Abstract: An apparatus (1) for the calibration of optical measuring instruments (10) with a carrier (2). According to the invention the calibration body (4) has a glass body (4) which has at least one scattering element (42), wherein this scattering element (42) is completely surrounded by the glass body (4), wherein a degree of transmission of the scattering element (42) and of the glass body differ from each other.

Abstract: An apparatus for measuring optical properties of transparent materials with a first illumination device which illuminates the material to be investigated along a pre-set illumination path with a pre-set radiation, with a radiation recording space which records radiation passed on by the material to be investigated. The radiation recording space is arranged so that radiation emitted by the first illumination device first strikes the material and then at least for a time an inner wall of the radiation recording space. A radiation detector device is arranged to record radiation reflected and/or scattered essentially only from the inner wall. A second illumination device suitable for emitting modulated radiation also illuminates the inner wall.

Abstract: An apparatus for measuring optical properties of transparent materials with a first illumination device which illuminates the material to be investigated along a pre-set illumination path with a pre-set radiation, with a radiation recording space which records radiation passed on by the material to be investigated. The radiation recording space is arranged so that radiation emitted by the first illumination device first strikes the material and then at least for a time an inner wall of the radiation recording space. A radiation detector device is arranged to record radiation reflected and/or scattered essentially only from the inner wall. A second illumination device suitable for emitting modulated radiation also illuminates the inner wall.