Dräger Safety Ag&co. Kgaa

Other

Dragerwerk Aktiengesellschaft

Drager Sicherheitstechnik Gmbh

Wilfried Diekmann

Mladen Schlichte

Matthias Martens

Andreas Sürig

Hans-Jürgen Bahs

Christoph Clausen

Ulrich Heim

Burkhard Stock

Rigobert Chrzan

Christoph Maurer

Andreas Nauber

Michael Sick

Stephan Haupt

Björn Lange

Christoph Bernstein

Edmund Koch

Johann Otten

Nils Haack

Dieter Krüger

Lars Wulf

G&uuml;nter Wahlbrink

Marcus Oertel

Jens-Uwe Hagenah

Dieter Krueger

A method for testing a gas sensor and a gas-measuring device with a testing device for testing the gas sensor provides an improved analysis and evaluation of states of gas sensors. Due to a testing of a gas admission element, by monitoring measuring signals (, () in a time course () in conjunction with dispensing () a quantity of test substance, it is made possible to check whether a gas supply to the gas sensor is possible (to check if the gas diffusion path is open) and given.

Method for testing a gas sensor and gas-measuring device with a testing device for testing a gas sensor

A gas detection device has at least one functional device (), which is configured to receive radiation () passing through a defined monitoring area (). At least one analysis unit () is configured to detect and analyze a change in the received radiation (). The received radiation () is based on the interaction of the radiation () with a gas present within the monitoring area (). At least one camera () has a field of view () that at least partially detects the monitoring area ().

Gas detection device

A method for testing a gas sensor () and a gas-measuring device with a testing device for testing the gas sensor () make possible an improved analysis and evaluation of states of gas sensors (). Due to the testing of a gas admission element () by monitoring measured signals () in a time course () and a comparison with threshold values () at predefined times (), (&#x2033;) in conjunction with the dispensing () of a quantity of test substance (), it is possible to test whether a gas supply () to the gas sensor () is possible and given.

A gas detection device with at least one functional device (), which is fixed to a platform, is pivotable about at least two pivot axes () relative to the platform. The functional device () is designed to emit and/or receive or reflect radiation that is analyzably variable due to the presence of a gas to be detected. The gas detection device has an adjusting device (), which has a fixing device for temporary fixation to the platform and an application device for the defined application on the functional device () of forces that lead to a pivoting about the pivot axes (). The application device acts detachably on the functional device ().

A device for optical detection of a target gas in gas mixtures includes an operation and evaluation unit, a measurement cuvette with optically reflective surfaces on its interior walls and a gas inlet to the environment, a radiation source, a measuring detector and a reference detector unit provided on the measurement cuvette. The measuring detector and the reference detector unit detect the light of the radiation source and produce electrical signals corresponding to the intensity of the detected light. An optical bandpass filter element, constructed to transmit light of a measurement wavelength, is arranged upstream of the measuring detector. An optical double-bandpass filter unit, that transmits light of a first reference wavelength and light of a second reference wavelength, is arranged upstream of the reference detector unit. The operation and evaluation unit operates the radiation source and acquires the electrical signals of the measurement detector and the reference detector unit.

Device with a measurement arrangement for optical measurement of gases and gas mixtures, with compensation of environmental effects

A process is provided for measuring a gas concentration with at least one thermal measuring element. The thermal measuring element is operated by pulses. A measured value of the gas concentration in the environment of the measuring element is obtained from the evaluation of the response of the measuring element to at least one single pulse by determining transient states of the thermal measuring element. From this the measured value of the gas concentration in the environment of the measuring element can be derived, during the imposed pulse based on electric measured variables.

Process for measuring the concentration of gases

A measuring device for determining the concentrations of gases by radiation absorption. The device includes at least one radiation source for generating radiation, a measuring cell, which is arranged downstream of the radiation source and in which the medium to be measured is located and at least one radiation detector, which is reached by the radiation after it has been sent through the measuring cell. A radiation guide device is provided by which the radiation is guided to the radiation detector. The radiation guide device includes a main optical unit, which has, on the one hand, an optical element (), so that the punctiform radiation source is imaged in a bar-shaped radiation spot () extending along a preferred direction (), and which has, on the other hand, parallel reflection surfaces (), which extend at right angles to the preferred direction and at the inner surfaces of which the radiation is totally reflected between the optical element () and the radiation detector ().

Measuring device

A gas sensor () with a detector element (), which is specific to a gas to be measured and sends a measured signal that depends on the measured gas concentration, has increased measuring sensitivity for measurements in the concentration range from less than 1 ppb to a few ppb. The detector element () is exposed in a gas admission adapter () to a gas to be measured via a diaphragm () arranged in front of the detector element (), wherein the gas admission adapter () has at least a first opening () for the entry of the gas to be measured as well as at least a second opening (), which is connected with a pressure modulator, which generates periodic gas pressure vibrations in the gas admission adapter () and is designed, for example, as a pump ().

Gas sensor with increased measuring sensitivity

A robust gas sensor can be manufactured in a simple manner and at low cost, and have no movable optical components. A measured gas cell () has a wall defining a cylindrical space with a measured gas inlet. The measured gas cell () is limited in the longitudinal axial direction by a reflective, flat first cover element () and by a reflective, flat second cover element () arranged at a spaced location from and in parallel to the first cover element (). The height of the measured gas cell () corresponds approximately to 1 to 3 times the diameter of the cover elements (). The second cover element () accommodates a radiation source () and two detector elements () with at least one measuring detector and one reference detector. The radiation source () is arranged displaced by 30% to 60% of the radius of the second cover element () from the center of the second cover element (). Both detector elements () are displaced by an amount of 25% to 35% of the radius of the second cover element (), which amount is equal for both detector elements (), from a straight line passing through the center of the second cover element (), wherein the straight line extends at right angles to the diameter of the radiation source (), and the direction of displacement of the detector elements () is opposite that of the radiation source (). The detector elements () are arranged mirror symmetrically to each other and at equal distance from the diameter of the radiation source (), wherein the distance amounts to 10% to 50% of the radius of the second cover element ().

Optical gas sensor

An optical gas sensor has a compact design and without movable optical elements, with at least one radiation source ( ), at least one measuring detector ( ) and a reference detector ( ). The reflecting measuring cuvette is designed as an annular space ( ) between a first, inner cylinder section ( ) and a second, outer cylinder section ( ) that is concentric thereto. The annular space ( ) is limited by a cover element ( ) and a bottom element ( ) arranged at a spaced location therefrom in the direction of the longitudinal axis. The cover element ( ) is permeable to the measuring gas. The bottom element ( ) accommodates the radiation source ( ).

A breath alcohol measuring apparatus includes a sample intake channel ( ) for receiving the respiratory gas sample and a temperature sensor mounted in the sample intake channel ( ). The breath alcohol measuring apparatus is so improved that the influence of the mouthpiece on the detection of the temperature of the respiratory gas sample is substantially eliminated. The temperature sensor is configured as an infrared optical thermometer ( ) with a filter ( ) transmissive for the infrared radiation. The filter ( ) is disposed in the sample intake channel ( ).

Breath alcohol measuring apparatus having a sample intake channel and a temperature sensor mounted therein

An infrared optical gas sensor is improved with respect to the quality of the measured signal. The infrared radiation detectors ( ) used as the reference radiation and measuring radiation detectors include thin layers of a partially transparent material, which sends an electric measured signal that depends on the radiation intensity received. The infrared radiation detectors are arranged stacked one over the other and with an interposed narrow-band filter ( ) each, which are transparent at the measuring wavelength. The infrared radiation detectors have an electrically conductive coating on the top side and the underside and are contacted. The measuring radiation detector ( ) follows the reference radiation detector ( ) in the direction of the beam and the reference radiation detector ( ) is transparent for at least part of the measuring radiation at the measuring wavelength, or the reference radiation detector follows the measuring radiation detector in the direction of the beam, and the measuring radiation detector is transparent for at least part of the reference radiation at the reference wavelength.

Infrared optical gas sensor

The invention is directed to a method of operating a laser diode in a measuring system for spectroscopically measuring the concentration of a gaseous component in a gas sample. This method is improved in that the mode jumps of the laser diode are easily recognized when adjusting the temperature-current operating point of the laser diode. An optical filter is placed in the beam path for adjusting the temperature-current operating point of the laser diode and, by changing the temperature T and the operating current I of the laser diode while simultaneously receiving the output signal supplied by an evaluation unit, the spectral positions of the mode jumps of the laser diode are determined which are included in the absorption lines of the gas sample. Thereafter, the temperature-current operating point is adjusted so that the distance of this operating point to the positions of the mode jumps is not less than a fixed spacing. The invention is also directed to a measuring system for spectroscopically measuring the concentration of a gaseous component in a gas sample.

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Lübeck, Germany

Wilfried Diekmann