Abstract: A device for guiding a person along a traveled path enables the wearer of the device to be guided back along the traveled path in an electronically supported manner even under conditions under which orientation is difficult. The device has a portable ejection means (2), in which a container (14) for accommodating a plurality of transponders (7) and an ejection mechanism (10), which is actuated by a control device (6) to eject a transponder (7) from the container (14), are present. A control unit (6) is prepared such as to actuate the ejection mechanism (10) at predetermined time intervals or at predetermined distances in space. A portable transmitter/receiver device (8) is designed to detect at least one of the transponders (7) dropped off and to generate a signal representative of the direction in which that transponder (7) is located. A portable display device (4) receives the direction signal of the transmitter/receiver means (8) and offers the wearer a visual and/or acoustic display of the direction.

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 is provided for putting an electrode carrier on a recumbent patient. The device includes a first lifting cushion that supports the shoulder region and the head of the patient at the same time and into which a pressurized medium can be admitted. A second lifting cushion is provided that supports the lumbar region and into which pressurized medium can be admitted. A spacer is provided fixing the lifting cushions in relation to one another in the chest region.

Abstract: An electrode belt for impedance tomography shall be improved such that it has a simple design and makes possible good contacting of the electrodes (2) with the body of the test subject to be examined. The electrode belt (1) has at least 16 electrodes (2) on an electrode holder or belt material (3), which is elastic at least in some sections. The belt formed of one or more belt material sections completely surrounds a test subject to be examined on the circumference of the body. Electrode feed lines (63) extend along the electrode holder (3). The electrode feed lines and are connected to a feed line (6) at least at one feed point (4) on the electrode holder (3).

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: An optical absorption measuring instrument for determining the percentage of a component in a fluid shall be improved such that changes in the measuring radiation caused by drift or temperature have only a limited effect on the measuring result. Provisions are made for deflecting the measuring beams (10, 11) from a radiation source (4) to a detector (5) by at least two plane mirrors (71, 72), which are positioned such that the measuring beams (10, 11) emitted by the radiation source (4) are deflected to the detector (5). The surface of each plane mirror (71, 72) is dimensioned to be such that its illuminated surface in the area of the detector (5) is larger than the receiving surface (12) of the detector (5).

Abstract: An optical absorption measuring instrument for determining the percentage of a component in a fluid shall be improved such that changes in the measuring radiation caused by drift or temperature have only a limited effect on the measuring result. Provisions are made for deflecting the measuring beams (10, 11) from a radiation source (4) to a detector (5) by at least two plane mirrors (71, 72), which are positioned such that the measuring beams (10, 11) emitted by the radiation source (4) are deflected to the detector (5). The surface of each plane mirror (71, 72) is dimensioned to be such that its illuminated surface in the area of the detector (5) is larger than the receiving surface (12) of the detector (5).

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: A codable gas detection system with at least one interchangeable gas sensor (2), which has standardized plug-type connections (5,6) between the gas sensor (2) and the measuring device (1), but is also able to prevent measured values of an unauthorized gas sensor (2) from being processed. Each gas sensor (2) contains a memory (3) with gas sensor-specific data and is connected via a line to the measuring device (1) with a first calculating and evaluating unit (7), to a downstream memory (8) and preferably to an alarm device (10). Via the second plug-type connection (5), the sensor element (4) proper is connected to a contacting unit (9) in the measuring device (1), and the contacting unit (9) is connected to the first calculating and evaluating unit (7), on the one hand, and to a downstream, second calculating and evaluating unit (11) for the measured value evaluation proper, on the other hand.

Abstract: A method for determining the portion of an electrochemically detectable substance in a gas sample includes the steps of introducing the gas sample into an electrochemical measuring cell 1 and generating a measurement curve i(t) by the electrochemical conversion of the substance in the measuring cell 1. The measuring curve i(t) increases from a reference line to a maximum value i.sub.max and drops back again to the reference line. Then, the maximum value i.sub.max and an area A below the measuring curve i(t) are determined. The area A is proportional to the portion of the substance in the gas sample. The method is improved in that a new measurement value is made available after a short time. This is achieved in that the maximum value i.sub.n max and the area A.sub.n of a previous measurement are compared to each other and a proportionality factor K.sub.n is determined. The proportionality factor K.sub.n is given by the ratio of the area A.sub.n to the maximum value i.sub.

Abstract: The invention relates to a method for operating an amperometric measuring cell which includes at least a measuring electrode 2 and a counter electrode 3 in an electrolyte chamber 4 filled with an electrolyte. The measuring cell is closed off by a permeable membrane 7 with respect to the measurement sample to be detected. The method of the invention improves the run-in performance of the measuring cell 1. The method includes the step of applying a voltage U.sub.1 across the electrodes (2, 3) during a first time span T.sub.1 starting at a reference time T.sub.0. A reference voltage U.sub.0 is assumed at the start of the measurement and the voltage U.sub.1 is increased relative to the reference voltage U.sub.0.

Abstract: The invention is directed to a measuring cell for electrochemically detecting a gas sample and has at least one measuring electrode and one counter electrode disposed in a housing defining a chamber filled with an electrolyte. The measuring cell also includes a protective disc which is at least partially permeable and is improved so that the configuration of the measuring cell is substantially simpler and is of reduced volume without reducing the ion mobility in the electrolyte and with a significant supply of the electrolyte. The counter electrode is in the form of a layer and is applied to a region of the protective disc facing toward the electrolyte. This region is impermeable to the gas sample and to the electrolyte. The counter electrode is further electrically insulated from the measuring electrode and is in permanent contact with the electrolyte. Only the measuring electrode and the diffusion membrane are applied to a region of the protective disc which is permeable to the gas sample.

Abstract: The invention is directed to a measuring apparatus for detecting gases with the aid of an electrochemical sensor with a diffusion barrier being disposed ahead of the sensor. The measuring apparatus is improved in such a manner that the sensor is adaptable with respect to its sensitivity to different measuring ranges during operation without external intervention. The speed of response of the sensor is also increased. Diffusion openings in the diffusion barrier are closable with a valve arrangement associated with the valve openings. The valve arrangement is connected via a valve drive unit to a measurement value comparator for changing the operating position of the particular valve to be actuated.

Abstract: A process for determination of one component of very low concentration in a test gas, which is guided in a supply line for concentration of the component across a sample collector, whose amassed quantity of samples is relinquished to a detection sensor. The arrangement makes available a measurement signal even during the collection of the sample. It also makes even the individual components of a multicomponent test gas detectable and a component-specific cross sensitivity of the detection sensor controllable. For this, the following process steps are provided: the test gas is first guided across the detection sensor 3 and then across the multistaged sample collector 7 having arrangements for separation of the several components; then after interruption of the supply of test gas, each individual stage 4, 5 and 6 separately relinquishes its separated component to the detection sensor 3.

Abstract: The invention is directed to a measuring cell for an electrochemical gas sensor having an electrolytic chamber and a measuring electrode as well as a counter electrode. In the direction facing the ambient, the measuring electrode includes a diffusion membrane as well as a diffusion barrier. The diffusion barrier is made of a material which is a good conductor of heat and is provided with a plurality of passages. A temperature-sensitive element is provided in the immediate proximity of these passages and faces toward the ambient. With this configuration, the temperature dependency of the diffusion capacity of the gas sample passing through the diffusion barrier can be included in the processing of the signal indicative of the measurement.

Abstract: The invention is directed to an apparatus for sensing a gaseous component in air and includes a housing having a flushing chamber through which an air sample can flow via a closeable inlet and a closeable outlet. The sensor is mounted in a measuring chamber above the flushing chamber and is hermetically sealed from its ambient not only during the time that the flushing chamber is flushed with the air sample; rather, and most important, during the measuring operation itself in order that any influences from a diffusion of the ambient air into the measuring chamber is prevented. For this purpose and to determine the sample quantity diffusing into the measuring chamber at the beginning of a specific period of time, the inlet as well as the outlet of the flushing chamber is closed while at the same time the diffusion passage interconnecting the two chambers is opened. After the time period has run, the diffusion passage is again closed.

Abstract: A test tube for combustible gases is intended to be provided with protective devices, so that, in proving the presence of combustible gases, it cannot become an ignition source. To that end, a flame arrester is arranged in front of and/or behind the test material.

Abstract: A gas measuring and warning apparatus is disclosed having a testing tube through which the gas that is to be detected flows. The apparatus also has a photoelectric scanner for detecting the migrating reaction zone. The configuration of the apparatus is simplified and the resolution capacity is improved. This is achieved in that the photoelectric scanner includes an image forming lens system which forms an image of the length of the reaction zone on a photosensitive array of identical sensor elements, the reaction zone being illuminated by at least one light source. For emitting a measured signal, the evaluation circuit is controlled by the number of sensor elements that are located within the imaged length of the reaction zone.

Abstract: When in use for a relatively long time and during the period of operational readiness, semiconductor gas sensors for measuring gas components of a gas mixture exhibit decreasing sensitivity and increased aging, so that if a relatively large quantity of the gas component that is to be measured is encountered they emit either no signal at all or at least an overly feeble signal. A method is disclosed to improve sensitivity and to attain a rapid reaction to the gas that is to be measured. The method is performed by continuously exposing the sensor to a stabilizing concentration having a defined amount of the gas component that is to be measured, particularly during absence of the gas component that is to be measured. A sensor wherein the method of the invention is carried out is also disclosed.

Abstract: A circuit arrangement is disclosed for correcting the output of a sensor which experiences changes in sensitivity due to the presence of one or more influencing factors, such as the concentration of a material to be sensed, or the passage of time. The circuit arrangement includes a correction network which generates a simulated sensitivity curve which simulated curve is combined with the output of the signal to produce a corrected output signal which has apparent constant sensitivity.