Abstract: A vehicle gas emission analyzer assembly for a vehicle having a passenger compartment includes a gas analyzer system adapted to determine concentration and/or mass flow of at least one exhaust gas of an internal combustion engine. The analyzer may include a particular housing for the gas analyzer system. The gas analyzer system may include a hydrocarbon gas analyzer that is operated at a temperature that is sufficiently high to reduce deposits of hydrocarbon molecules present in the sample gas. The gas analyzer may include an ultraviolet source including a discharge lamp having a discrete emission line at an absorption frequency for a particular nitrogen-based gas.

Abstract: A method and an apparatus for the selective determination of an isotope portion of a measuring gas by means of non-dispersive spectroscopy. The method includes sensitizing in a first ray path to the isotope component and sensitizing in a second ray path to the isotope-pure measuring gas, and electronically amplifying the measurement results. In order to improve the selectively and the sensitivity while maintaining a simple construction, an additional optical filtering is carried out in the first ray path by a filter filled essentially with isotope-pure measuring gas and the electronic measuring value of the second ray path is entered by influencing the amplification factor and an offset in the electronic amplification of the first ray path.

Abstract: A sensor device which registers the amount of moisture on a transparent screen. The sensor is connected to at least one light conducting element which is provided on one side with at least one beam emitter and on the other side with at least one beam receiver. The light conducting element is provided with a layer of reflecting material to enable multiple reflection of the beam issuing from the beam emitter.

Abstract: A thermal mass flow-meter used in particular for corrosive and hot gases. It includes a flow duct having at least two measuring resistors. At least one of these is arranged in the flow cross-section. At least one heat source is provided in the zone of influence of the measuring resistors; heat source and measuring resistance may be identical. For the purpose of obtaining long-term resistance to corrosion accompanied by great sensitivity as regards response, the measuring resistors consist of a thin-film resistor with a ceramic insulating member, a measuring resistor is connected to a ceramic support member by way of glass solder, and the support member is in turn connected to the flow duct by way of a glass solder element.

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: In an infrared radiation source, especially for a multi-channel gas analyzer, a radiant body (3) is provided with a reflector (4) disposed behind it, and a window (5) of calcium-fluorite at least partially covering the radiant body (3) is provided, the radiant body (3) being partially surrounded at its rear by a cup-like case (6) whose circumferential margin is hermetically joined to the window (5) by an intermediate ring (19). The interior (7) of the radiant source can be pumped empty of air through a passage (8) in a tube connection (9) formed by the case (6) or provided with an oxidizing atmosphere, thereby achieving a high insensitivity to the position of the infrared radiation source.

Abstract: In an apparatus for determining the concentration of foreign matter in a water stream, a stream of liquid is bypassed through conduits both before and after the pipeline block for the process and each stream is pumped into a cell, a beam source being associated with each of the cells whose beams penetrate the cells and are led by a beam splitter both to a first detector and to a second detector, the electrical signals of the detectors being compared by an electrical circuit and processed to a recognition signal. To make a bubble-free sample stream possible, magnetically actuated valves are inserted into the return lines which are connected to the cells, and the signals for opening and closing the valves are produced by a frequency generator.

Abstract: Apparatus for measuring the thermal conductivity of a gas has first and second, heatable and temperature-dependent measuring resistors in sufficiently close, tandem proximity along a flow path for the gas and connected in opposite arms of a measuring bridge circuit.

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.