Abstract: A measurement gas vessel (3) for the measurement of the concentration of gas components of a stream of breath from a patient has a thin-walled inner part (11) which has two opposite facing walls limiting the breath stream. The walls are transparent to infrared light. An outer part (10) which in the central region (7) has two recesses on opposite sides which, with the walls (16) of the inner part (11), each form a window (9). A region of the inner part (11) outside the windows (9) is thermally connected to the outer part (10), and the outer part (10) surrounds the inner part (11).

Abstract: A measurement gas vessel (3) for the measurement of the concentration of gas components of a stream of breath from a patient has a thin-walled inner part (11) which has two opposite facing walls limiting the breath stream. The walls are transparent to infrared light. An outer part (10) which in the central region (7) has two recesses on opposite sides which, with the walls (16) of the inner part (11), each form a window (9). A region of the inner part (11) outside the windows (9) is thermally connected to the outer part (10), and the outer part (10) surrounds the inner part (11).

Abstract: The invention relates to an apparatus and a method for improved correction of drift in an infrared measuring instrument. The measurement signal furnished by a thermal detector is split into a direct voltage component and an alternating voltage component. By means of calibration curves (24, 27), a calculated comparison variable T DC , korr 900 is formed from a measured, averaged concentration value c AC1 900 . The correction value ?T for the drift correction is obtained from the difference between the corresponding measured size of the direct voltage component T DC 900 and the comparison variable T DC , korr 900 .

Abstract: The invention relates to an apparatus and a method for improved correction of drift in an infrared measuring instrument. The measurement signal furnished by a thermal detector is split into a direct voltage component and an alternating voltage component. By means of calibration curves (24, 27), a calculated comparison variable T DC , korr 900 is formed from a measured, averaged concentration value c AC1 900 . The correction value ?T for the drift correction is obtained from the difference between the corresponding measured size of the direct voltage component T DC 900 and the comparison variable T DC , korr 900 .

Abstract: A device and process are provided for determining the concentration of at least one gas component in a breathing gas mixture. The device is used especially to determine the concentration of a trace gas for a lung function measurement. The requirements on such a device are compact design with low weight, and the requirement on the process is high speed of measurement. For the case of the determination of the concentration of a gas component in a breathing gas mixture, the device has two detectors designed as thermopiles (3, 4) for the infrared optical radiation of a radiation source (1), of which the first thermopile (3) is used alternatingly as a reference detector and for the determination of the concentration of a trace gas for the lung function measurement, and the second thermopile (4) is used to determine the concentration of a gas component in the breathing gas mixture.

Abstract: A process is provided for determining the functional residual capacity (FRC) of the lungs during respiration. An environmentally friendly trace gas is used in a process and system for determining the FRC by using fluoropropanes as a trace gas. Values for the FRC can thus be calculated, resolved for individual breaths, from the expiratory trace gas concentration and the expired breathing gas volume and they can be used for determining the FRC depending on their convergence behavior.

Abstract: A process is provided for determining the functional residual capacity (FRC) of the lungs during respiration. An environmentally friendly trace gas is used in a process and system for determining the FRC by using fluoropropanes as a trace gas. Values for the FRC can thus be calculated, resolved for individual breaths, from the expiratory trace gas concentration and the expired breathing gas volume and they can be used for determining the FRC depending on their convergence behavior.

Abstract: A measuring device for determining the concentration of gases with two identical radiation sources and two radiation detectors, which delivers stable measured values despite the contamination that occurs or the shielding from radiation of the outer optical surfaces exposed to the gases or to mixtures of gases and despite possible mechanical disadjustments. The two radiation detectors are provided with an optical concentrator each for bundling the radiation, and being arranged in a gas-tight housing together with the two identical radiation sources and with a beam splitter. One radiation source is directed through a window that is transparent to infrared light to a plane mirror outside the gas-tight housing, and the beam path reflected by the plane mirror falls through the window that is transparent to infrared light onto the beam splitter.

Abstract: The invention is directed to a sensor arrangement for optically measuring the components of a gas. The sensor arrangement includes a housing containing a transmitter, a receiver device, a heatable holder for a measuring cuvette and optical devices for establishing the beam path. The sensor arrangement is improved by limiting the heating of the cuvette walls to those areas which lie in the beam path without the pass-through area of the optical devices being narrowed by the heating device. Also, the cuvette walls are heated in the manner described above without electrical contacts being disposed on the cuvette or on the sensor. The heatable cuvette holder includes one window disposed in the beam path which is transmissive for the measuring radiation. When the cuvette is seated in the cuvette holder, this window lies in virtual contact engagement with the cuvette and has a surface facing away from the cuvette.