Abstract: An electrochemical gas sensor, which has a substantially more compact design and is manufactured with a considerably reduced manufacturing effort. A conical, calotte-shaped, hemispherical or cylindrical outer housing is provided with gas admission openings (3, 203). A cover (8, 208) as well as a layer structure is provided with, from the outside to the inside, the diffusion membrane (4, 204) with the electrodes (5, 6, 7; 205, 206, 207) applied thereto in a planiform manner, a layer (11, 211) consisting of a mat material or a porous body, which accommodates the electrolyte, and an electrolyte space (10, 210), which is filled at least partially with the electrolyte.

Abstract: A process and a device are provided for monitoring the hydrogen concentration in a gas with at least one device, which comprises an electrochemical gas sensor and a bipotentiostat, e.g., for use in internal combustion engines with hydrogen, in fuel cells and in the petrochemical industry. The electrochemical gas sensor used has two working electrodes (3) and (4), with which the hydrogen and oxygen concentrations are determined in the gas in different steps due to the application of a voltage by a bipotentiostat (5-18). In an additional, optional step, a voltage in the range of −1,100 mV to −800 mV is applied to a working electrode (4), so that hydrogen is formed at the working electrode (4) and the functional surface of the working electrode (4) as well as the sensitivity of the working electrode (3) to hydrogen can be checked.

Abstract: An electrochemical gas sensor, which has a substantially more compact design and is manufactured with a considerably reduced manufacturing effort. A conical, calotte-shaped, hemispherical or cylindrical outer housing is provided with gas admission openings (3, 203). A cover (8, 208) as well as a layer structure is provided with, from the outside to the inside, the diffusion membrane (4, 204) with the electrodes (5, 6, 7; 205, 206, 207) applied thereto in a planiform manner, a layer (11, 211) consisting of a mat material or a porous body, which accommodates the electrolyte, and an electrolyte space (10, 210), which is filled at least partially with the electrolyte.

Abstract: An electrochemical gas sensor (1) is disclosed with a plurality of electrodes (2, 3, 4). The sensor has substantially reduced cross sensitivity with respect to interfering gases. At least the measuring electrode (2) is provided as a thin layer of diamond-like carbon (DLC, diamond-like carbon) on the gas-permeable membrane (9).

Abstract: An electrochemical gas sensor for detecting a specific gas being measured with a plurality of electrodes (21, 3, 4), an electrolyte (7) and a gas-permeable membrane (9) has a reduced cross sensitivity with respect to interfering gases, a short response time and high sensitivity for the measured gas without the service life being reduced. The measuring electrode is a layer of doped diamond thin (21) on a porous substrate (22), where the gas-permeable memebrane is disposed over the measuring electrode to permit passage therethru of the gas being measured.

Abstract: An electrochemical gas sensor with a plurality of electrodes (21, 3, 4), an electrolyte (7) and a gas-permeable membrane (9) has a reduced cross sensitivity with respect to interfering gases, a short response time and high sensitivity for the measured gas without the service life being reduced. The measuring electrode is a layer of doped diamond (21) on a porous substrate (22).

Abstract: An adapter (1) and electrochemical gas sensor (2) is provided with an electrochemical gas sensor housing (14) accommodating an electrolyte (13), with at least one measuring electrode (12) arranged therein and with a membrane (11), which screens the measuring electrode (12) from a measured gas and is permeable to the measured gas. The measuring sensitivity of an electrochemical gas sensor is increased by the adapter (1) having a gas-impermeable surface (15) extending in parallel to and at a spaced location from the membrane (11). The adapter (1) and the membrane (11) form a flow gap (10) for the measured gas delivered by a pump. The adapter (1) may be plugged onto the electrochemical sensor (2) at its outer edge (1a). The measured gas enters through a central opening (17) , expands in the flow gap (10) radially to the outside and leaves same via the ring-shaped gap (16).

Abstract: An electrochemical gas sensor has at least one measuring electrode (5), a reference electrode (11) and an auxiliary electrode (7) in an electrolyte (3) and a diffusion membrane. The diffusion membrane (4) is formed from a polymer (Teflon® AF) containing bis-2,2-trifluoromethyl-4,5-difluoro-1,3-dioxol. The diffusion membrane (4) faces the ambient atmosphere.

Abstract: The invention is directed to an electrochemical measuring cell for detecting hydride gases, preferably arsine and phosphine. The measuring cell includes at least one working electrode (3) made of a catalytically inactive material and a reference electrode (4) in an electrolyte chamber (6) filled with an electrolyte containing sulphuric acid. The measuring cell is improved as to the cross sensitivity with respect to other toxic gases. The working electrode is configured as a carbon electrode (3) and an electrolyte additive of silver sulphate is provided in saturated solution in the electrode (9).

Abstract: An electrochemical oxygen sensor with a measuring electrode, an atmospheric oxygen electrode as a reference electrode, and an auxiliary electrode in an electrolyte is improved such that a stable measured signal is obtained even during changes in the position of the measuring cell. To accomplish this, the auxiliary electrode is arranged in the vicinity of the measuring electrode and a protective electrode is provided between the measuring electrode and the auxiliary electrode.

Abstract: An electrochemical measuring cell for detecting arsine and phosphine, containing at least one working electrode (3) consisting of a catalytically inactive material and a reference electrode (4) in an electrolyte space (6), which is filled with an aqueous electrolyte (9) and is sealed with a gas-permeable membrane (2) toward the gas to be detected, shall be improved in terms of the cross sensitivity to other gases. To accomplish this object, the working electrode (3) is designed as a thin-layer electrode and the electrolyte (9) consists of sulfuric acid with an electrolyte additive consisting of silver sulfate.

Abstract: A filter for an electrochemical measuring cell with a filter housing and a filter material contained therein is improved, with a simple design, such that interfering gas components cannot reach the measuring cell from the gas mixture. This is accomplished by the filter housing being formed of a porous, gas-permeable material.

Abstract: The invention is directed to an electrochemical measuring cell to detect different gas components. The measuring cell includes several measuring electrodes (12, 15, 18) and a counter electrode 30 in an aqueous electrolyte 3. The measuring cell is improved with respect to the selectivity of the detection of the different gaseous components. A step-like offset 34 is provided between one of the measuring electrodes 12 and another measuring electrode 15.

Abstract: An electrochemical measuring cell for detecting oxidizing gases, containing an electrode with a redox mediator, which is oxidized by the gas to be detected. A measuring electrode is employed made of an inert material, and a counterelectrode is provided. The dynamics and reproducibility of the measured signal are improved by providing the counterelectrode formed of an anodically oxidizable material and is arranged behind the measuring electrode in the direction of diffusion in a sandwich-like arrangement.

Abstract: A gas sensor has at least a measuring electrode and a counter electrode on an electrolyte layer. This gas sensor is improved with respect to the complete extent of the electrochemical reaction achieved of the gas molecules, which are to be detected, at the measuring electrode by the manner of determining an electrical charge developed or accumulated thereat. To solve this task, the invention provides that the measuring electrode (14) has component electrodes (14a, 14b) which enclose the electrolyte layer (11, 12) in the manner of a sandwich.

Abstract: The present invention pertains to an electronic measuring cell for detecting components in fluid media. Such a measuring cell is to be improved such that hermetic sealing of the contact wires leading out of the measuring cell is possible in a housing of a slightly modified design to prevent electrolyte from escaping. To achieve this, an annular space extending in parallel to the circumferential direction of the housing between the measuring cell cover and the housing is filled with an electrolyte- and temperature-resistant sealing material, and the contact wires are led through.

Abstract: The invention is directed to an electrochemical measuring cell for detecting gaseous constituents in air. The measuring cell includes a measuring electrode and a counter electrode accommodated in a housing. The housing includes an electrolyte chamber and the electrolyte is in liquid contact with the electrodes. The measuring electrode is in diffusion contact with the gas constituents to be detected via a gas-permeable membrane which is impermeable to the electrolyte. The measuring cell is improved so that an effective pressure equalization between the electrolyte chamber and the ambient is made possible in the context of a simple assembly of the housing. For this purpose, the housing jacket surrounding the electrolyte chamber has at least one breakthrough. The electrolyte chamber is separated from the ambient by a gas-permeable stop disposed in the breakthrough. This stop is impermeable to the electrolyte.

Abstract: An electrochemical sensor for fluid media with at least two electrodes, which are in contact with one another via an electrolyte and are accommodated in a housing. Many different sensor variants are attainable with a few, standardized components. The housing (1) includes a plurality of modules (4a, 4b; 4c-4m), which are placed next to one another, are designed as hollow bodies, and are connected to one another, wherein at least two lateral surfaces (9) of each module (4a-4m) are suitable for connection to additional modules (4a-4m), and at least two of the modules (4a, 4b; 4c-4m) accommodate one electrode (2, 3) each, and the hollow space (16) enclosed by the modules (4a, 4b; 4c-4m) is delimited from the environment by the two electrodes (2, 3), on the one hand, and by a partial area (17) each of the inner wall (5) of the modules (4a, 4b; 4c-4m), and is provided for accommodating the electrolyte (18).

Abstract: The invention is directed to an electrochemical cell for measuring ammonia, amines, hydrazine and hydrazine derivatives and includes a measuring electrode in an electrolyte. The measuring electrode is provided with a coating made of a transition metal oxide and is improved in that its measuring sensitivity during long-term loading is increased. The cross sensitivity of the measuring cell is reduced especially with respect to NO.sub.2 and SO.sub.2. For this purpose, the oxide constituents of the coating are made of a metal conducting oxide of one element or an oxide mixture of several elements of the platinum metal group. Oxides of ruthenium and iridium have proven especially useful. The invention is also directed to an electrochemical measuring cell for measuring ammonia or hydrazine and includes at least a measuring electrode and a counter electrode in an electrolyte. The measuring cell provides a signal increase having a shorter response time and an improved signal stability.

Abstract: An electrochemical measuring cell has a three-electrode system including electrode, counter electrode and reference electrode in an electrolyte. The measuring cell has an additive promoting the electrochemical reaction and is selective and highly sensitive for the detection of hydrogen halides and also provides a stable measuring signal. A measuring cell of this kind has an additive of tetrachloroauric acid in the electrolyte for detecting hydrochloric acid with all electrodes being made of gold. The counter electrode is protected by a cation exchange membrane to provide a further improvement.