Abstract: An electrochemical sensor element, in particular for determining the oxygen level in gas mixtures, includes at least one measuring electrode exposed to a measured gas, at least one reference electrode exposed to a reference gas, at least one heating device, and one reference gas channel, through which the reference gas can be supplied to the reference electrode. The reference electrode is connected to the reference gas via a volume provided with pores. The volume is formed in a layer between the reference gas channel and the reference electrode.

Abstract: An electrochemical sensor element is described, in particular for determining the oxygen level in gas mixtures, having at least one measuring electrode (15) exposed to a measured gas, at least one reference electrode (17) exposed to a reference gas, at least one heating device (23), and one reference gas channel (21), through which the reference gas can be supplied to the reference electrode (17). The reference electrode (17) is connected to the reference gas via a volume provided with pores. The volume is formed in a layer between the reference gas channel (21) and the reference electrode (17).

Abstract: An electrochemical measuring sensor having a solid electrolyte, a first electrode exposed to a gas to be measured and a second electrode exposed to a reference gas, with the electrodes preferably being arranged on opposite sides of the solid electrolyte. At least one of the electrodes (16, 20) is provided with a contouring (24) on its side (22) that is exposed to the gas to be measured or to the reference gas, with the contouring being a trench-shaped groove (26) embossed into the surface of the electrode such that the electrode is pressed into the adjacent solid electrolyte in the region of the groove. According to the method, the embossing is done while the electrode and the solid electrolyte are in the non-sintered state, and the sensor is subsequently sintered.

Abstract: A planar polarographic sensor for determining the lambda value of gas mixtures, for use with exhaust gases in internal combustion engines, includes a planar ceramic carrier sheet having an outer pumping electrode and an inner pumping electrode respectively arranged on opposite planar sides thereof, and a diffusion barrier. The outer and inner pumping electrodes, and the diffusion barrier are arranged on the planar ceramic carrier sheet so that the measuring gas is fed via the diffusion barrier to the inner pumping electrode. The sensor has front and side edge faces. The diffusion barrier is configured as a diffusion layer at least partially covering the inner pumping electrode and exposed at least at one edge face of the sensor to the measuring gas. A diffusion-free planar region of the sensor is provided with an equalizing layer having the same thickness as the diffusion layer, and the equalizing layer is disposed in the same plane with and adjacent to the diffusion layer.

Abstract: A planar polarographic probe for determining the .lambda. value of gas mixtures, in particular of exhaust gases of internal combustion engines, having at least the following units: a pumping cell (A), a diffusion unit (B) with a diffusion resistance preceding a pumping electrode of the pumping cell (A) and, if necessary, a heating unit (C) is proposed in which the diffusion resistance of the diffusion unit (B) is formed by a preshaped body which becomes porous on sintering and which is inserted into the unsintered probe.Such a polarographic probe enables a sensor to be constructed in a simple manner which is particularly suitable for production, with increased reproducibility of the diffusion resistance.

Abstract: To retain a plate-like sensing element, for example made of ceramic, in position within a metallic housing without danger of breakage or loosening under conditions of vibrations or shock or wide swings of temperature and substantial temperature gradients, a metallic housing has a longitudinal opening wherein in which two sealing elements are located, for example made of aluminum oxide. The sealing elements are formed, each, with an internal pocket, for example extending conically outwardly towards their meeting surfaces, to form a chamber. The chamber is filled with a resiliently compressible powder or pulverized material, for example talcum, and separates the elements by a gap (31) extending outwardly to the walls of the metallic housing. The sensor element is passed through slits formed in the end regions of the sealing elements (26, 27) and is retained in position by the compressible powder or pulverized material.

Abstract: To provide an easily manufactured and easily connected heater element for a tubular ion-conductive body (26) forming a sensing element (24) of the oxygen sensor, the heater element (35) comprises a plate-like substrate (36) of insulating material, e.g. ceramic, which, at its inner end is wider than at the end fitting into the inside of the tubular ion-conductive body, the conductors leading to the heater being formed as conductive tracks spaced apart from each other by a greater distance at the inner end, adjacent connection zones (37/3), than close to the heater zone (37/1), the plate-like substrate, at the inner portion, being essentially trapezoidal and terminating in an end edge (36') which forms the wider side of the trapezoid.

Abstract: A gas measurement probe has a casing (11) equipped with a closure shell (17) on its end away from the gas to be measured. At the other end of the casing, within its longitudinal bore, a sensor element (24) is held fast and tight in the casing. A rod-shaped part carrying a heater element fits within the sensor element and extends out of it at its end away from the gas to be measured to an extremity near which contact areas are provided on its periphery. On these contact areas, resilient connection wires lie under mechanical bias. These wires, between the loops bearing against the contact surface and their ends are bent in Z or sinuous shape so as to secure them against pulling, twisting and shaking forces. These connection elements and also another conductor running in the probe cooperate with an indexing feature of the rod-shaped element, such as a suitable groove to secure the rod-shaped component against twisting.