Abstract: An optical measuring cell for measuring gas absorption with a light source for introducing light into a measuring volume and a light sensor located approximately opposite the light source in the direction of light propagation and relative to the measuring volume for receiving light that is guided through the measuring volume is provided. The concentration of one or multiple target gases in the measuring volume is detected by an evaluation unit. The measuring volume is constituted by an internal volume of a hollow fiber having an internal diameter less than 1 mm.

Abstract: A fuel system is disclosed for a floating unit, including a fuel passage extending from a filler neck to a motor, a measuring unit disposed in the fuel passage through which at least part of the fuel flowing along the fuel passage flows, for measuring a sulfur content of the fuel through the measuring unit.

Abstract: A FET gas sensor having a relatively low operating temperature, for example, room temperature, is free from cross sensitivities from interfering gases by a preceding in-line filter. The sensor's service life is substantially stabilizable by using fabric-like activated charcoal filters which can be regenerated by a moderate temperature increase, and by limiting the diffusion of the analyte gas, which is made possible by the relatively small amount of gas detectable on the sensitive layer of the sensor. This substantially increases the service life of the filters. The gas sensor eliminates cross sensitivities to thereby increase the detection reliability thereof. Also, the gas sensor has relative long term stability and is economical to build. The gas sensor can read relatively weak signals generated by gas-sensitive layers, for example, without other stronger gas signals interfering with the weak signals.

Abstract: A gas sensor based on a field effect transistor (“FET”) evaluates both a change in work function of a gas-sensitive layer of the FET and a change in the capacitance of the layer. Thus, two physically independent signals are read from the gas-sensitive layer, each signal representing a sensitivity to a different gas. This reduces the effect of cross-sensitivities; that is, of one gas on the target gas. The underlying physical mechanisms, the first causing a change in the work function in a reaction with gases and the second causing a change in the capacitance of the sensitive layer, are widely different. Because of this, the two parameters demonstrate different gas sensitivities. If the reactions to both gases are known, the effect of the interfering gas on the sensor signal can be compensated for, and with this the concentration of the target gas can be determined.

Abstract: A fuel system is disclosed for a floating unit, including a fuel passage extending from a filler neck to a motor, a measuring unit disposed in the fuel passage through which at least part of the fuel flowing along the fuel passage flows, for measuring a sulfur content of the fuel through the measuring unit.

Abstract: A gas sensitive field effect transistor comprises a semiconductor substrate that includes a capacitance well, and source and drain regions of a field effect transistor. A gate of the field effect transistor is separated from the semiconductor substrate by an insulator, and a gas sensitive layer separated from the gate by an air gap. The field effect transistor provides an output signal indicative of the presence of a target gas within the air gap to an amplifier, which provides an amplified output signal that is electrically coupled to the capacitance well.

Abstract: An optical measuring cell for measuring gas absorption with a light source for introducing light into a measuring volume and a light sensor located approximately opposite the light source in the direction of light propagation and relative to the measuring volume for receiving light that is guided through the measuring volume is provided. The concentration of one or multiple target gases in the measuring volume is detected by an evaluation unit. The measuring volume is constituted by an internal volume of a hollow fiber having an internal diameter less than 1 mm.

Abstract: An operating method is disclosed for the selective detection of a target gas in a gas mixture to be measured by a field effect transistor with a gas-sensitive layer disposed on a carrier substrate, wherein the gas mixture to be measured is prepared by an electrochemical element such that the measured gas mixture includes minimal amounts of interfering gases that interfere with the measurement of the target gas, and/or at least one target gas is activated such that it is detected by the gas-sensitive layer.

Abstract: A FET gas sensor having a relatively low operating temperature, for example, room temperature, is free from cross sensitivities from interfering gases by a preceding in-line filter. The sensor's service life is substantially stabilizable by using fabric-like activated charcoal filters which can be regenerated by a moderate temperature increase, and by limiting the diffusion of the analyte gas, which is made possible by the relatively small amount of gas detectable on the sensitive layer of the sensor. This substantially increases the service life of the filters. The gas sensor eliminates cross sensitivities to thereby increase the detection reliability thereof. Also, the gas sensor has relative long term stability and is economical to build. The gas sensor can read relatively weak signals generated by gas-sensitive layers, for example, without other stronger gas signals interfering with the weak signals.

Abstract: An FET-based gas sensor includes at least one field-effect transistor and at least one gas-sensitive layer and a reference layer. Any changes in work function occurring when materials of the layers are exposed to a gas are used to trigger the field-effect structures. The gas-sensitive layer includes a metal oxide having an oxidation catalyst on its surface and accessible to the measured gas.

Abstract: A gas-sensitive field-effect transistor may be formed from a substrate with a gas-sensitive layer and a transistor processed separately and then assembled. The substrate may be patterned to form spacers by which the height of an air gap between the transistor and the sensitive layer may be adjustable to a relatively precise degree. Formation of the spacers can be achieved by patterning the substrate using material-removal techniques. The height of the spacers may be adjusted in the layer thickness of the gas-sensitive layer and for the transistor fabricated using a CMOS process. Suitable techniques for producing recesses between the spacers include, for example, polishing, cutting, sandblasting, lithographic dry etching, or wet-chemical etching. Suitable materials for the substrate may include, for example, glass, ceramic, aluminum oxide, silicon, or a dimensionally stable polymer.

Abstract: A gas sensor based on a field effect transistor (“FET”) evaluates both a change in work function of a gas-sensitive layer of the FET and a change in the capacitance of the layer. Thus, two physically independent signals are read from the gas-sensitive layer, each signal representing a sensitivity to a different gas. This reduces the effect of cross-sensitivities; that is, of one gas on the target gas. The underlying physical mechanisms, the first causing a change in the work function in a reaction with gases and the second causing a change in the capacitance of the sensitive layer, are widely different. Because of this, the two parameters demonstrate different gas sensitivities. If the reactions to both gases are known, the effect of the interfering gas on the sensor signal can be compensated for, and with this the concentration of the target gas can be determined.

Abstract: A gas-sensitive field-effect transistor (GasFET) for the detection or measurement of an amount of hydrogen sulfide present in ambient air includes a raised gate electrode and a transistor structure. The raised gate electrode may be formed from or coated with a gas-sensitive material such as tin oxide, or silver, silver oxide or mixtures thereof. An insulator layer may be disposed on top of the transistor structure. An air gap is formed between the gas-sensitive layer of the raised gate electrode and the insulator layer on top of the transistor structure.

Abstract: The invention relates to an FET-based gas sensor comprising a gas channel for diffusing a measuring gas to a gas-sensitive layer which is actively connected to a FET for signal readout. According to the invention, an electrochemical element is at least partially inserted into the gas channel for the electrochemical conversion of interfering gases. The arrangement is permeable to the target gas.

Abstract: An FET-based gas sensor includes at least one field-effect transistor and at least one gas-sensitive layer and a reference layer. Any changes in work function occurring when materials of the layers are exposed to a gas are used to trigger the field-effect structures. The gas-sensitive layer includes a metal oxide having an oxidation catalyst on its surface and accessible to the measured gas.

Abstract: Method of effecting a readout of a gas-sensitive field-effect transistor having an air gap between a gate electrode with a gas-sensitive layer and the readout transistor, in which a potential occurring on the gas-sensitive layer in the presence of a target gas is passed through a noncontacting floating gate electrode to the transistor, wherein the potential of a reference electrode, which together with the floating gate electrode generates a capacitance Cw, is tracked to the potential of the floating gate electrode in order to eliminate the capacitance Cw during the measurement.

Abstract: A gas-sensitive field-effect transistor may be formed from a substrate with a gas-sensitive layer and a transistor processed separately and then assembled. The substrate may be patterned to form spacers by which the height of an air gap between the transistor and the sensitive layer may be adjustable to a relatively precise degree. Formation of the spacers can be achieved by patterning the substrate using material-removal techniques. The height of the spacers may be adjusted in the layer thickness of the gas-sensitive layer and for the transistor fabricated using a CMOS process. Suitable techniques for producing recesses between the spacers include, for example, polishing, cutting, sandblasting, lithographic dry etching, or wet-chemical etching. Suitable materials for the substrate may include, for example, glass, ceramic, aluminum oxide, silicon, or a dimensionally stable polymer.

Abstract: A method for measuring the quality properties of paper and/or board on moving webs is disclosed. The present invention utilizes a staged evaluation method in which the basic properties of the paper or board and further properties are determined via multi-stage modeling.

Abstract: A method for measuring the quality properties of paper and/or board on moving webs is disclosed. The present invention utilizes a staged evaluation method in which the basic properties of the paper or board and further properties are determined via multi-stage modeling.

Abstract: A sensor assembly for sensing gaseous or fluid medium such as sensing oxygen within exhaust gas of an automobile. The assembly provides a sensor element within a housing mounted within a S-shaped flow channel between a medium entry aperture and exit aperture. A shield is provided upstream of the sensor in a flow direction of the medium. The arrangements provide for a laminar flow across the sensor element causing reduced deposits on the surface of the sensing element for a more accurate sensor and a longer service life of the sensor element.