Dragerwerk Aktiengesellschaft

Other

Dräger Safety Ag&co. Kgaa

Robert Kessel

Horst Rabenecker

Andreas Nauber

Matthias Martens

Matthias Studer

Gero Sagasser

Fritz Thiele

Andreas Huth

Thomas Treptow

John Cohen

Marko H Wittich

G&uuml;nter Wahlbrink

Kathleen Leahy

Bernd Fassian

A gas-measuring device has an electrochemical sensor and features such that the readiness for use is guaranteed for a determined period of time. A status display (), is activated by the evaluating circuit () of the gas-measuring device. The status display () displays the degree of depletion of the sensor.

Gas-measuring device with an electrochemical sensor

A modular gas measuring system with a basic unit () with electric supply and data lines connected to it, a measuring unit (), which is equipped with a gas sensor and with a microprocessor and is connected to the basic unit () by means of snap closures to form a functional unit. At least one expansion module, is accommodated by the functional unit. The modular design, of optionally accommodating different expansion modules, so that the properties and the possible applications of the gas measuring system can be expanded in a simple manner.

Modular gas measuring system

The invention is directed to a method for measuring gas concentrations with a measuring head which is provided with a satellite-supported global positioning device. With the method, gas concentrations at various locations can be determined. The position of the measuring head is determined at predetermined time intervals and first position data of a previously measured first position is compared to second position data of a current position. When a predetermined limit value between the first position data and the second position data is exceeded; a measured value of gas concentration corresponding to the current position together with the second position data are stored in a data memory of the measuring head.

Method for measuring gas concentrations

A process is provided for improving the reliability of operation of optical gas sensors with at least one radiation source and with at least one radiation detector. By comparing and evaluating the measured signals (,) (D) sent by the radiation detector, of which there is at least one, with first, second and third stored reference values (D,, D,, K), it is achieved, on the one band, that in the case of toxic gas concentrations or of gas concentrations that are critical because of explosion hazard, second measured values (,) continue to be sent for the protection of the user corresponding to the range between the reference values D,and D,when the third reference value (K) is exceeded. On the other hand, at least first warning signals (,) are sent by the gas sensor to warn that a preset degree of contamination has been reached in order for maintenance or cleaning of the gas sensor to be performed or in order for the gas sensor to be replaced with a new gas sensor shortly.

Process for improving the reliability of operation of optical gas sensors

The present invention pertains to an electrochemical gas sensor, which has an electrode system for the measurement and is directly coupled with the environment via a gas inlet. To avoid fault liability and incorrect measurements in the case of rapid changes in atmospheric humidity, a moisture reservoir is provided according to the present invention at the gas inlet, and the moisture reservoir is designed to reversibly exchange moisture with the gas atmosphere surrounding it, following the relative humidity of the gas atmosphere, in order to buffer or damp variations in the relative humidity of the gas atmosphere acting on the electrode system. The moisture reservoir may have, e.g., a container body, whose walls have moisture-permeable areas, which face the gas atmosphere in the gas sample volume or the gas diffusing into it, and in which hygroscopic substances are contained. For example, salt solutions, highly concentrated acids or silica gel, which extract moisture from the environment when the humidity of the ambient air increases and release the moisture when the humidity of the ambient air decreases, may be contained in the container body.

Electrochemical gas sensor

An electrochemical measuring cell for detecting phosgene, with at least one measuring electrode made of silver and with a counterelectrode in an electrolyte, which contains an organic solvent and to which a conductive salt is added, is improved in terms of the detection of low concentrations of phosgene by adding an amine to the electrolyte.

Electrochemical measuring cell for detecting phosgene

A device for the selective detection of a component from a gas mixture comprises a selective prefilter for retaining the other components of the gas mixture, a measuring unit arranged downstream of the selective prefilter for the component to be detected, and a pump pumping the gas mixture. The use of a photoionization detector as a downstream measuring unit makes possible a continuous display operation.

Device for the selective detection of a component in a gas mixture

An amperometric sensor detects acidic and alkaline gases utilizing a first pH-dependent reversible redox system on a measuring electrode 4. A reduction current occurs between the measuring electrode 4 and a counter electrode 6 for a constant potential and is used as a measurement variable of the concentration of the gas to be detected. In addition, a reference electrode 5 is disposed in an electrolyte 7 together with the measuring electrode 4 and the counter electrode 6. The gas to be detected penetrates through the permeable membrane 2 and is dissolved while being dissociated. The amperometric sensor is improved with respect to its permanent stability. This is provided in that the first pH-dependent redox system is coupled to a second redox system and the redox potential of the second redox system is so selected that the reaction product is chemically regenerated again to the educt via the second redox system. The reaction product is electrochemically formed at constant potential by the first redox system.

Growing community of inventors

Bad Oldesloe, Germany

Robert Kessel