Dräger Safety Ag&co. Kgaa

Björn Lange

Nils Haack

Rigobert Chrzan

Mladen Schlichte

Lars Wulf

Burkhard Stock

Wilfried Diekmann

Ingo Kaneblei

Thomas Wuske

Rainer Polzius

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

An explosion-proof sensor for detecting combustible gases is provided with a glass seal () for establishing an electrically conductive connection with the interior of the housing. The sensor is improved in terms of the pressure resistance of the housing. The glass seal () has a bending-resistant casting compound () mechanically stabilizing the glass seal () on at least one side.

Explosion-proof sensor

Tempering of sample () in test strip () is carried out by temperature regulating unit () and heating/cooling unit (). The sample is fed to the test strip by a developer fluid () and a metering unit (). The result of the detection reaction becomes visible by a change in color (), which is detected optically and analyzed. The data of a control chart () with the measured values of first and second temperature sensors () are used to set the control parameters for tempering. Code () on the test sample holder () is read in a sequence of steps. Parameters for phases of the measurement are determined from measured values of first and second temperature sensors, values of the control chart and the code of the test sample holder. These parameters are used by the temperature regulating unit during the measurement.

Process for putting into operation and for operating a measuring device

A gas sensor () has a pressure-tight sensor housing (). The sensor housing () has a metal plate () at its lower end and the metal plate () has breakthroughs (). Metal pins () electrically contact the sensor elements () and these metal pins are brought to the outside via glass inserts ().

Gas sensor for detecting combustible gases

A gas sensor is provided that is delimited from the environment with a preferably replaceable cap () made of a porous, gas-permeable and water-impermeable material, especially sintered PTFE. The gas sensor is protected against environmental moisture and can be permanently provided with the cap () and with a special calibrating adapter () both during the gas measurement and during the necessary calibration. Due to the special design of the cap () and the calibrating adapter (), the gas sensor offers the possibility of remote calibration, which can be carried out with high accuracy and is independent from weather effects, especially wind.

Gas sensor

An explosion-proof gas sensor has a measuring element (), which generates a measured signal that depends on the concentration of the measured gas and is delimited against the environment by means of a porous, gas-permeable and sintered metal body (). The sintered metal body () has a high mechanical stability, so that the use of additional components, which hinder the diffusion of the gas to be measured into the gas sensor and thus prolong the response time of the gas sensor, can be eliminated.

Growing community of inventors

Teschow, Germany

Björn Lange