Abstract: A gas sample vessel for a gas analyzer comprising a housing enclosing a cylindrical resonator cavity. Two mirrors which limit the resonator cavity are fastened to the housing for coupling in and feeding back the measurement light proceeding from an illumination source. The mirrors are curved concavely at their surfaces facing the housing and the housing is curved convexly at its surfaces facing the mirrors with approximately the same radius of curvature. The centers of curvature lie in the center axis of the resonator cavity and the mirror surfaces of the mirrors are portions of the concavely curved surfaces facing the housing.

Abstract: A method and a device are disclosed for determining the thickness and growth rate of an ice layer on structural component parts, particularly of aircraft, wherein the thickness and growth rate of an ice layer are determined and displayed in a simple, economical and dependable manner. To this end, a method is disclosed by which the radiation incident on a surface covered by an ice layer or disturbing layer is separated spectrally by a holographic grating connected with a line receiver into enough wavelength regions that a correction of the ice absorption is achieved by comparing the measured radiation with a stored reflection curve of an uncoated surface and by combining the comparison values and determining the peak area in the wavelength region of the ice absorption, and wherein from the thickness of the ice layer and disturbing layer and the ice thickness values obtained in the measurement intervals the growth rate of the ice layer is determined and displayed.

Abstract: In order to provide an arrangement for pressure compensation for optical devices, particularly spectrometers or the like optical devices, for compensating pressure differences caused by changes in temperature and air pressure between the internal pressure and the external pressure at a housing of an optical device enclosing optical units, which arrangement prevents a contamination of optical functional surfaces of the optical units of the optical device and ensures a constant pressure balance between the interior space and the external surroundings of the housing of an optical device with its optical units while economizing on manufacturing costs, it is proposed that the arrangement for pressure compensation comprises at least one pressure compensating element which is constructed on both sides so as to be permeable to air and which is arranged in a housing opening of the housing wall of the optical device enclosing the optical units.

Abstract: An arrangement for fixing an optical component part in position in a device housing, comprising a holder which is connected to a housing and which presses the component part into a cutout in the housing accompanied by pretensioning. The holder is fashioned in one piece from elastic material and is provided with clamps that are formed integral with it, at least one of which clamps presses the component part against a reference plane in direction of one of the coordinates X, Y, Z accompanied by pretensioning, and fastening elements are formed integral with the holder for securing it to the housing.

Abstract: A gas sample vessel for a gas analyzer comprising a housing enclosing a cylindrical resonator cavity. Two mirrors which limit the resonator cavity are fastened to the housing for coupling in and feeding back the measurement light proceeding from an illumination source. The mirrors are curved concavely at their surfaces facing the housing and the housing is curved convexly at its surfaces facing the mirrors with approximately the same radius of curvature. The centers of curvature lie in the center axis of the resonator cavity and the mirror surfaces of the mirrors are portions of the concavely curved surfaces facing the housing.

Abstract: A method and a device are disclosed for determining the thickness and growth rate of an ice layer on structural component parts, particularly of aircraft, wherein the thickness and growth rate of an ice layer are determined and displayed in a simple, economical and dependable manner. To this end, a method is disclosed by which the radiation incident on a surface covered by an ice layer or disturbing layer is separated spectrally by a holographic grating connected with a line receiver into enough wavelength regions that a correction of the ice absorption is achieved by comparing the measured radiation with a stored reflection curve of an uncoated surface and by combining the comparison values and determining the peak area in the wavelength region of the ice absorption, and wherein from the thickness of the ice layer and disturbing layer and the ice thickness values obtained in the measurement intervals the growth rate of the ice layer is determined and displayed.

Abstract: An arrangement for fixing an optical component part in position in a device housing, comprising a holder which is connected to a housing and which presses the component part into a cutout in the housing accompanied by pretensioning. The holder is fashioned in one piece from elastic material and is provided with clamps that are formed integral with it, at least one of which clamps presses the component part against a reference plane in direction of one of the coordinates X, Y, Z accompanied by pretensioning, and fastening elements are formed integral with the holder for securing it to the housing.

Abstract: In a background compensation in material analysis, the value of the background signal is separated from the value of a gross analyte signal generated by athermal radiation excitation after thermal excitation. The thermal atomization takes place in a stepwise manner by stepwise heating and each step is divided into a first part for the measurement of the gross analyte signal and a second part for the measurement of the background signal.

Abstract: An adjustable Echelle spectrometer arrangement which can be used in single- and multi-element analysis by the emission or absorption of optical radiation. To compensate all the manufacturing and setup errors, the only arrangements present are those to change the height of the entry slit arrangement above the base plate and to rotate the dispersion prism about a first axis, approximately parallel to its roof edge, and about a second axis, that is vertical thereto. This compensates for the effect of errors associated with component and setup parameters which results from greater tolerances, without impairing mechanical and thermal stability and imaging quality.