Abstract: In a self-supporting beam-splitter (1), in particular for use in an FTIR-spectrometer for the far-infrared region, with an optical thickness on the order of the interesting wavelength region, the foil beam-splitter (1) consists of an undoped semi-conducter material or carbon which is transparent in the far-infrared, and is preferentially made from thin silicon sheets or diamond foil in the thickness region between 2 .mu.m and 125 .mu.m. In this fashion, an extremely high efficiency for the beam-splitter is achieved, whereby little or no resonant absorption takes place due to the beam-splitter in the interesting wavelength region.

Abstract: A method for routine identification of materials of plastic components with the assistance of infrared spectroscopy with which an infrared reflection spectrum is taken from the surface of a plastic component to be investigated and compared to a set of reference spectra, whereby the material of the plastic component under investigation is correlated to a class of plastic materials represented by one of the reference spectrum, is characterized in that the plastic component under investigation is positioned with the assistance of a video device (25, 26) and in that the infrared reflection spectrum is recorded in the range of the mid-infrared (MIR) in a wave length region between 400 and 4,000 cm.sup.-1. In this fashion even plastics which, for example, are filled with carbon can be routinely identified. It is preferred when the first derivative of the recorded IR spectrum with respect to wave number is taken and compared to the first derivative of the IR spectra of the reference spectra.

Abstract: The invention concerns an optical or infrared Fourier spectrometer with a plurality of entrances and exits for the coupling on of external sources or samples. The entrances can also be used as exits and vice versa.

Abstract: In an infrared (IR) microscope for a Fourier transform (FT) infrared spectrometer with a Cassegrain mirror-lens with which an incident beam (15) can be focused via a convex mirror (16) and a concave mirror (17) onto a first point-shaped region (19) on the surface of a sample (20) under an angle of incidence .beta.<60.degree.

Abstract: An optical or Fourier infrared Fourier spectrometer with a two-beam interferometer with which the mirror drive is effected via two retroreflectors which are located on two 180.degree. displaced arms of a double pendulum. Deflecting mirrors are arranged between the beam splitter and the retroreflectors. The otherwise usual retroreflecting mirrors are not present. The beam splitter is displaced with respect to the plane of the pendulum. Thereby, a stable, easily aligned, and compact configuration is effected.

Abstract: A sample holder for placing a sample substance for transmission measurements with optical radiation into a spectrometer, in particular, a FTIR spectrometer which is at least partially made from a material transparent to the optical radiation in a intermeshing wavelength region and which exhibits an index of refraction in excess of 1 is configured as a converging lens with a concave surface (11) and a convex surface (12). To take an absorption spectrum of a powder and/or fluid dissolved or suspended sample substance, the sample substance is brought onto the concave surface (11) of the sample holder before the measurement where it, in consequence of the curvature and in contrast to a flat surface, is concentrated in a substantially smaller surface region. The configuration of the sample holder as a converging lens increases the yield of the radiation penetrating through the sample substance onto the detector of the spectrometer configuration.

Abstract: In an IR-FR- spectrometer, a light beam (10) is guided from a source to a detector (31) and is passed, in a first mode of operation, by means of first optical means (12, 19, 20) through a sample to be measured (28) and, in a second mode of operation, by second optical means (12, 22, 21) through a reference sample (32). The first and second optical means comprise a common mirror element (12) having at least first and second mirror surfaces (13, 14, 15, 16) which are inclined relative to each other. The mirror surfaces abut in at least one point. There is provided means for moving the mirror element (12) relative to the light beam so that during such relative movement the impinging point of the light beam (10) is displace from the first mirror surface (13), over onto the second mirror surface (14).

Abstract: An infrared spectrometer comprises first optical means for focussing a beam of light in a point-shaped area of a sample (19), second optical means for focussing upon a detector (26) the light emitted by the sample, and third optical means permitting the visual observation of the point-shaped area (19). The second optical means of this arrangement are so designed that they pick up the light reflected by the point-shaped area (19). The arrangement of the invention permits measurements to be performed on extremely small areas and even on samples which are not or hardly pervious to light in the infrared range.

Abstract: An auxiliary device enabling reflection measurements to be carried out by an IR spectrometer designed for the performance of transmission measurements comprises two deflecting mirrors (22, 23) to be positioned in the straight beam section of the spectrometer and two focussing reflector arrangements (26, 2, 27) of which the first forms at the location of the sample (16) to be investigated by the reflection method a reduced image of the focus (30) situated within the ray of beams (28) deflected by the first deflecting mirror (22) while the said second focussing reflector arrangement forms an enlarged image of the said reduced focus at a distance before the said second deflecting mirror (23) so that the beam of rays (33) emitted by the said second deflecting mirror forms a prolongation of the beam of rays inciding upon the said first deflecting mirror just as if the auxiliary device did not exist.

Abstract: A modular system for performing optical spectroscopy measurements comprising enclosed modules with ports through which optical beams may pass into and out of the modules. The modules may be joined together with the ports aligned and are interchangeable in the sense that the focal point of the optical beam directed out of any output port has the same location relative to the output port.

Abstract: A sample chamber for an optical spectrometer comprising means for selecting one of two modes of operation: a transmission mode or a reflection mode. The mode-selecting means comprise optical elements for switching the path of the optical beam passing through the sample chamber so that the beam either passes through a sample or is incident upon and reflects off of a surface of a sample. Coupled to the path-selecting means are means for moving a sample to the position and orientation relative to the optical beam which is appropriate to the mode of operation selected.