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: 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: A measuring head for the determination of the concentration of a paramagnetic gas in a gas sample has first and second housing parts (21, 2) made of a steel alloy for accommodating a magnet coil body (4, 5) each. The magnet coil bodies extend concentrically around the central axis of each housing part (21, 2). Metallic bars (31, 3), which are used as magnet poles for the measuring head, are located at spaced locations with a defined air gap in the assembled state of the measuring head. The bars are arranged in the center of the measuring head in the area of the central axis of the housing parts (21, 2). A sample gas cuvette support (6) is provided in the air gap between the housing parts (21, 2) for positioning a sample gas cuvette holder (1). The sample gas cuvette support (6) is provided with a gas inlet and gas outlet (8, 81).

Abstract: A highly compact measuring gas cell for a device for measuring the concentration of a paramagnetic gas on the basis of the change in the thermal conductivity of the paramagnetic gas, which is brought about by a change in the magnetic field. The measuring gas cell has a bottom plate (1) that carries a measuring element (1.4) for the detection of the thermal conductivity of the measured gas, electric leads, an electric measuring gas cell heater (1.2) and a temperature-dependent electric sensor element (1.3) for the detection of the temperature of the measuring gas cell. A channel plate (2) is cut out for the gas guide in the area of the measuring element (1.4) and around the measuring element (1.4). A cover plate (3), seals the measuring gas cell in the upward direction and has at least two holes for the inlet and outlet of the gas into and out of the gas guide of the channel plate (2).

Abstract: A highly compact measuring gas cell for a device for measuring the concentration of a paramagnetic gas on the basis of the change in the thermal conductivity of the paramagnetic gas, which is brought about by a change in the magnetic field. The measuring gas cell has a bottom plate (1) that carries a measuring element (1.4) for the detection of the thermal conductivity of the measured gas, electric leads, an electric measuring gas cell heater (1.2) and a temperature-dependent electric sensor element (1.3) for the detection of the temperature of the measuring gas cell. A channel plate (2) is cut out for the gas guide in the area of the measuring element (1.4) and around the measuring element (1.4). A cover plate (3), seals the measuring gas cell in the upward direction and has at least two holes for the inlet and outlet of the gas into and out of the gas guide of the channel plate (2).

Abstract: A measuring head for the determination of the concentration of a paramagnetic gas in a gas sample has first and second housing parts (21, 2) made of a steel alloy for accommodating a magnet coil body (4, 5) each. The magnet coil bodies extend concentrically around the central axis of each housing part (21, 2). Metallic bars (31, 3), which are used as magnet poles for the measuring head, are located at spaced locations with a defined air gap in the assembled state of the measuring head. The bars are arranged in the center of the measuring head in the area of the central axis of the housing parts (21, 2). A sample gas cuvette support (6) is provided in the air gap between the housing parts (21, 2) for positioning a sample gas cuvette holder (1). The sample gas cuvette support (6) is provided with a gas inlet and gas outlet (8, 81).

Abstract: A device for measuring the flow of a fluid located in a fluid channel heats the fluid channel without additional components. A metallic tube (2) with predetermined thermoelectric potential is provided as a fluid channel. An a.c. power source (7) is connected to a partial section (6) of the tube (2) in such a manner that the partial section (6) is heated as a resistor element to an increased working temperature compared with the temperature of the fluid. At least one thermocouple (12) is provided with junction points formed along the partial section (6) in such a manner that at least two wires (8, 9) with another thermoelectric potential are connected to the tube (2) in the area of the partial section (6). A measuring circuit (13, 14, 15) evaluates the thermocouple voltage of the thermocouple (12) and has a circuit (13) which eliminates the a.c. voltage component superimposed to the thermocouple voltage as a consequence of the a.c. heating.

Abstract: The invention relates to a gas sensor with an open optical measurement path for optical measurement of at least one gas component, having a light source unit (1), a detector unit (2), between which units the optical measuring path (13) extends, and having a control and evaluation device; the light source unit (1) has a light source (3) and optical guide elements for transmitting a measuring light beam to the detector unit (2), and the detector unit (2) includes a detector (4), which when oriented in the beam path of the measuring light beam detects the intensity of light from the measuring light beam, and the control and evaluation device (11) is designed to determine, on the basis of the measurement signal of the detector (4), a standard for the concentration of the gas component to be investigated.

Abstract: A device for measuring the flow of a fluid located in a fluid channel heats the fluid channel without additional components. A metallic tube (2) with predetermined thermoelectric potential is provided as a fluid channel. An a.c. power source (7) is connected to a partial section (6) of the tube (2) in such a manner that the partial section (6) is heated as a resistor element to an increased working temperature compared with the temperature of the fluid. At least one thermocouple (12) is provided with junction points formed along the partial section (6) in such a manner that at least two wires (8, 9) with another thermoelectric potential are connected to the tube (2) in the area of the partial section (6). A measuring circuit (13, 14, 15) evaluates the thermocouple voltage of the thermocouple (12) and has a circuit (13) which eliminates the a.c. voltage component superimposed to the thermocouple voltage as a consequence of the a.c. heating.

Abstract: The object is to improve an apparatus for measuring the concentration of a paramagnetic gas in a gas sample, in such a way a measurement signal with a low noise ratio is obtained. The apparatus proposed according to the invention is characterized by a modulatable magnetic field source 4, 5, 6, 7 with an air gap 3 as a measuring chamber for receiving the gas sample; a modulation source 26 for outputting a modulation signal to the magnetic field source 4, 5, 6, 7; a measuring element 8, disposed inside the air gap 3 and heated to an operating temperature, for outputting a heat flow measurement signal; a filter device 28, 29, for filtering periodic fluctuations out, caused by the modulation of the magnetic field source, from the heat flow measurement signal caused by the modulation of the magnetic field source, the amplitude of the periodic fluctuations, being a measure for the proportion of the gas in the gas sample.

Abstract: A device for measuring the velocity of flow of a fluid, with at least one thermocouple (10), whose junction point is arranged in the fluid, with an a.c. power source (11) heating the thermocouple to a working temperature higher than the temperature of the fluid and with an evaluating circuit (12, 13) processing the thermocouple voltage, is to be improved such that the temperature dependence of the heat conductivity of the fluid to be investigated is compensated in a simple manner. To accomplish this object, the temperature coefficient of the ohmic resistance of the thermocouple (10) is adapted to the temperature dependence of the heat conductivity of the fluid such that the heating power converted in the thermocouple (10) during a change in temperature and unchanged current varies by exactly the same amount as the amount of heat released to the fluid due to the changed heat conduction.

Abstract: A process for operating a thermocouple (2), which is arranged in a gas atmosphere and is maintained at a working temperature that is increased compared with the gas temperature by means of an a.c. power source (11). The determination of the thermal power introduced into the gas atmosphere and the temperature measurement are made possible with one measuring element. The thermocouple voltage is compared with a predetermined reference voltage U.sub.B arising from the working temperature of the thermocouple, a difference signal is formed between the thermocouple voltage and the reference voltage U.sub.B, and the a.c. power source (11)is influenced with the difference signal such that the thermocouple voltage is maintained at a constant value relative to the reference voltage U.sub.B.

Abstract: A device for measuring the flow of a fluid in a fluid channel, with at least one thermocouple, whose thermojunctions are arranged one behind the other in the direction of flow of the fluid and are maintained at a working temperature higher than the fluid temperature by means of an ac power source 9. The thermocouple is connected to a measuring circuit evaluating the thermocouple voltage U.sub.T. Continuous measurement with high accuracy is possible with a measuring circuit having a switching network, by which the ac power source is connected to the thermocouple at least during the measurement phase, and by which the ac voltage components superimposed to the thermocouple voltage are eliminated by subtraction.

Abstract: The invention is directed to an apparatus for optically evaluating colorimetric coloration zones automatically wherein not only a single testing tube but also a plurality of reaction zones applied one behind the other to a common carrier can be evaluated. The least quantity of indicator substances for the coloration zones is used and an adequate signal intensity with the least possible consumption of power for the optical signal evaluation is attained. At the same time, the sensitivity to faults is reduced. Such an apparatus includes transmission as well as receiving units on a common mounting carrier. The light of the transmitting unit is conducted via a light conductor through the region of the reagent carrier which is transmittent and the coloration of the channel-shaped reaction zones of the carrier is detected in transmission and reflectance.