Abstract: In a method and apparatus for measuring the optical absorption of samples having a light source (1), a photoelectric converter (8), a measurement beam path extending between the light source (1) and the converter (8), in which path the sample to be examined is arranged, a reference beam path extending between the light source (1) and the converter (8), in which path a reference sample is arranged, and a motor-driven chopper disc (10), the chopper disc (10) is configured with a first number of first openings (15) unblocking only the measurement beam path and a second number of second openings (16) unblocking only the path for the reference beam.

Abstract: In a method and apparatus for measuring the optical absorption of samples having a light source (1), a photoelectric converter (8), a measurement beam path extending between the light source (1) and the converter (8), in which path the sample to be examined is arranged, a reference beam path extending between the light source (1) and the converter (8), in which path a reference sample is arranged, and a motor-driven chopper disc (10), the chopper disc (10) is configured with a first number of first openings (15) unblocking only the measurement beam path and a second number of second openings (16) unblocking only the path for the reference beam.

Abstract: A microrheoscopic detector for gases including two thin wire resistance thermometers and a heating conductor disposed between the two resistance thermometers, the resistance thermometers being positioned in the area of influence of the heating conductor and spaced therefrom in a definite spatial fixation, the heating conductor having a span transverse gas flow path and comprising a plurality of parallel conductor legs laying in the span in the same plane as the resistance thermometers.

Abstract: An apparatus for the producton of particular concentrations of gaseous materials as well as for mixing different gaseous materials in a specified ratio in which the gaseous materials are supplied from different sources in pulsed fashion to at least one common outlet. The gaseous materials are passed through a valve which has n inlets and m outlets, n and m being whole numbers. This valve can connect at least one inlet for a specifiable time with a particular outlet. The valves are controlled preferably by a pulse-width modulated method, for example by means of a microprocessor. A gas pump is connected downstream from the common outlet.

Abstract: Cell for gas analyzers, having a casing with a cylindrical bore which is divided by an axial wall of separation into two chambers. The one chamber serves for the gas being measured and the other for a reference medium. The chambers terminate in windows at both ends. To make such a cell resistant to pressure and corrosion, the reference medium is constituted by a transparent, glass-clear material which is disposed in the cylindrical bore. At each end of the cylindrical bore there is provided an annular shoulder for the support of an annular gasket and a window. The windows are held by annular compression flanges and annular gaskets.

Abstract: A pneumatic infrared radiation detector for intermittent irradiation with infrared light has a hermetically sealed chamber including a metal cup having a highly reflective inner surface forming the back of the chamber and a flange-like rim at the open end thereof. A radiation admitting window is disposed at the open end of the cup and a flow detector is connected to the chamber. The cup comprises a thin-walled noble metal vessel comprising one of gold and silver and the window is composed of at least one of calcium fluoride and barium fluoride and sealed vacuum tight to the cup with glass solder having a coefficient of expansion of between 110 and 150. 10.sup.-7 /K.

Abstract: A microrheoscopic detector for gases, especially for infrared gas analyzers comprises a base and a heating conductor mounted to the base. Two resistance thermometers are disposed in the area of influence of the heating conductor and comprise thin wire which is held between thicker connecting wires which are in turn affixed to the heating conductor.

Abstract: Process for the photo-optical measurement of the absorption behavior of solid, liquid and gaseous media. A measurement light beam from an optical radiation source is made intermittent by a rotating chopper comprising a rotatable metal wheel. The chopper frequency is maintained constant by regulation of the speed of the metal wheel by two alternating-current magnets inducing eddy currents to slow or speed up the wheel. The actual speed of the wheel is detected and compared with a reference speed and the magnitude of the excitation currents is adjusted on the basis of the rotatory speed difference to effect the regulation of the speed of the chopper.

Abstract: An apparatus for the photo-optical measurement of the absorption behavior of solid, liquid and gaseous media. A measurement light beam from an optical radiation source is made intermittent by a rotating chopper comprising a rotatable metal wheel. The chopper frequency is maintained constant by regulation of the speed of the metal wheel by two alternating-current magnets inducing eddy currents to slow or speed up the wheel. The actual speed of the wheel is detected and compared with a reference speed and the magnitude of the excitation currents is adjusted on the basis of the rotatory speed difference to effect the regulation of the speed of the chopper.