Abstract: An explosion-proof gas sensor (1) with a flashback barrier (2) permeable to the gas to be measured between the measuring space (4) and the environment in an otherwise gas-impermeable housing (3) is described. The sensor provides reduced response time and higher signal sensitivity for the gas to be measured. A flashback barrier (2) is provided including a plurality of flexurally rigid fabric layers made preferably of metal, which are permeable to the gas to be measured, with an overall thickness of one to ten mm, an overall porosity of at least twenty percent by volume relative to the volume of the flashback barrier (2), and with a maximum number of one percent of all pores with a pore size larger than 240 &mgr;m.

Abstract: A device for displaying the exhaustion of a gas filter filled with an adsorbent (3). A toxic gas detector (14) determines the toxic gas content at a sampling site (8) within the adsorbent (3). A reference sampling site (12) is located in the area of a gas inlet point (6) of the gas filter (2). The toxic gas detector is designed such that it determines the toxic gas content alternately at the sampling sites (8, 12), and the exhaustion of the filter is determined by a comparison of the toxic gas content at the sampling site (8) with the toxic gas content at the reference sampling site (12).

Abstract: A mobile measuring instrument that can be worn on the body of persons with a springless holder (1) for detachable fastening to pieces of clothing, with the following features: a plate (8) has a recess (9) with a cutout on one of two shorter sides; a flat slide element has a guide element (12) and is displaceably connected with same to the plate (8) via the cutout (10); both the plate (8) and the slide element (11) are provided with mutually parallel pins (2, 3; 4, 5) on the opposite, longer sides of the plate (8); the pins (2, 3) of the plate (8) are held stationarily rotatably in the housing (6) of the measuring instrument (7); and the pins (4, 5) of the slide element (11), which are arranged in two guides (17) in the housing (6) of the measuring instrument (7), are displaced between a maximum and a minimum distance from the pins (2, 3) of the plate (8), depending on the path of displacement of the slide element (11).

Abstract: A device comprising a combination of a mouthpiece (2) with a holder (1), which receives the mouthpiece (2) and has a sampling channel (4) leading to a breath alcohol-measuring device and a temperature sensor (11) arranged in the connection area between the holder (1) and the mouthpiece (2). To make it possible to determine the temperature of the mouthpiece (2) inserted into the holder (1) the mouthpiece (2) is designed for the temperature sensor (11) to be arranged in the sampling channel (4) as a wall section (10) covering the inner wall of the sampling channel (4) in the area of the temperature sensor (11).

Abstract: A scent cartridge (1) with a substrate (3), wherein the latter consists of porous particles of silica gel, activated carbon and/or aluminum oxide, which are impregnated with scents or active ingredients. The substrate (3) is fixed in a small cylindrical glass or aluminum tube (2) by means of wiremesh caps (4) made of metal or plastic. A membrane disk (6) is sealingly held on each flanged edge (5) of the small glass or aluminum tube (2) by means of a cap (7) each so that the membrane disks (6) can be punctured with needles or cannulae for releasing scents or active ingredients and an air or carrier gas flow controlled in a time-dependent manner is then admitted to the scent cartridge (1).

Abstract: A device is provided for taking swab samples and sample dilution. The device has a plug made of a porous, absorbent material, which projects from a sleeve and is used to take a swab sample. The plug is located in one end of the sleeve. A piston, which can be moved in the sleeve by means of a piston rod, is located in the other end of the sleeve. A closure, which can be opened by means of pressure, is located between the piston and the plug, so that a liquid arranged between the piston and the plug moves through the closure to the plug and wets same on actuation of the piston rod.

Abstract: A process for detecting dust-associated substances wherein the dust to be analyzed is brought together with a solvent for eluting the substance to be detected from the dust. The particulate components are retained by means of a filter matrix while the solvent and the substances dissolved and/or suspended therein are transported through the filter matrix by capillary liquid transport. The solvent and the substances dissolved and/or suspended therein are transferred into a reaction matrix adjoining the filter matrix by capillary liquid transport. The substance to be detected is detected in the reaction matrix by means of a chemical and/or biochemical reaction or by the failure of a chemical and/or biochemical reaction to take place. A device for detecting dust-associated substances preferably contains, besides the filter matrix and the reaction matrix, a container for receiving the dust to be analyzed, wherein the container is in liquid connection with the filter matrix.

Abstract: A process for calibrating a breath alcohol-measuring instrument (7) with a calibrating gas generator (1) with a liquid container (2) for aqueous ethanol solution and air feed device, which allow air to bubble through the ethanol solution and for passing gas from the atmosphere above the ethanol solution to the breath alcohol-measuring instrument (7).

Abstract: The invention is directed to an arrangement for blocking the operation by an intoxicated operator of a machine or a motor vehicle. The arrangement has a measuring apparatus which determines the blood alcohol content of the operator and an evaluation unit connected to the machine or motor vehicle. The evaluation unit receives measurement data supplied by the measurement apparatus and enables the machine or motor vehicle when the measurement data satisfies at least one predetermined condition. The arrangement is improved in that the sobriety of the operator is recognized before the starting operation of the machine or motor vehicle without it being necessary to supply a breath sample. The measuring apparatus includes a gas sensor which is a sensor for measuring the blood alcohol content via permeation through the skin of the operator. The measuring apparatus is configured so that it can be worn by the operator preferably on the leg or arm.

Abstract: An infrared measuring arrangement with essentially expanded measuring range with an infrared radiation source (3) and an infrared radiation detector (4). The infrared radiation source (3) has a first, direct beam path to the infrared radiation detector (4), on the one hand, and, on the other hand, a second, reflected beam path to the infrared radiation detector (4), which is longer than the first one.

Abstract: A detector tube with a rod-shaped reagent carrier placed into a transparent tube, which reagent carrier is provided with a detection substance, such that the reagent carrier can be placed into the detector tube in a simple manner and that defined flow conditions become established around the reagent carrier. The cross-sectional contour of the reagent carrier is designed as a polygon in such a way that at least some of the outer edges of the reagent carrier are in contact with the inner side of the tube.

Abstract: A device and a process for indicating the exhaustion of an adsorption filter to indicate a necessary filter change in time is provided. The monitoring device has a gas concentration-measuring device (8), a temperature-measuring device (9) for determining the temperature of the ambient air, a memory unit (3) with a first memory field (4), in which filter data sets associated with individual filters are stored, with a second memory field (5), in which data specific of toxic substances are stored, and with a third memory field (6), which contains preset values for the ambient air humidity and the respiratory minute volume, as well as an input unit (7) for selecting preset values from the memory fields (4, 5, 6). A timer (10) with a start button (13), which provides an output of the service life t of the adsorption filter is also provided.

Abstract: An electrochemical measuring cell for detecting arsine and phosphine, containing at least one working electrode (3) consisting of a catalytically inactive material and a reference electrode (4) in an electrolyte space (6), which is filled with an aqueous electrolyte (9) and is sealed with a gas-permeable membrane (2) toward the gas to be detected, shall be improved in terms of the cross sensitivity to other gases. To accomplish this object, the working electrode (3) is designed as a thin-layer electrode and the electrolyte (9) consists of sulfuric acid with an electrolyte additive consisting of silver sulfate.