Sensirion Ag

Andreas Rüegg

Mark Hornung

David Kiliani

Eric Monnin

Lukas Bürgi

Nicolas Moeller

Matthias Studer

Samuel Wehrli

Harry Figi

Thomas Huber

Nicolas Möller

Lucas Huber

Daniel Traeutlein

Philipp Reibisch

Daniel Traeutelein

A thermal sensor device serves for determining a concentration of a target gas in a gas sample that further comprises a disturbance gas. The thermal sensor device comprises first and second measurement structures () comprising first and second temperature sensors (TS, TS) and a heater element () operable to cause heat transfer to the measurement structures through the gas sample. Processing circuitry provides heating power (P_) to the heater element and derives an output signal (S) based on a response of the temperature sensors to the heating power, the output signal being indicative of a concentration of the target gas in the gas sample. The first and second measurement structures have different heat dissipation capabilities, and the processing circuitry derives the output signal from a weighted difference of temperature signals from the first and second temperature sensors. Thereby, a cross-sensitivity of the output signal to a concentration change of the disturbance gas may be reduced or eliminated.

Thermal sensor device and method for determining a concentration of a target gas in a gas sample

A regulation device for regulating a mixing ratio (x) of a gas mixture comprises a first conduit () for carrying a flow of a first gas (e.g., air) and a second conduit () for carrying a flow of a second gas (e.g., a fuel gas). The first and second conduits () open out into a common conduit () in a mixing region (M) to form the gas mixture. A first sensor (S) is configured to determine at least one thermal parameter of the gas mixture downstream from the mixing region. A control device () is configured to receive, from the first sensor, sensor signals indicative of the at least one thermal parameter of the gas mixture and to derive control signals for adjusting device (V) acting to adjust the mixing ratio, based on the at least one thermal parameter.

Device for regulating a mixing ratio of a gas mixture

A thermal sensor device is configured to determine a fluid parameter of a fluid based on the heat transfer behavior of the fluid. The sensor device comprises one or more heaters and means for determining a response of the sensor device to heater power being supplied to the heaters. For detecting sensor faults, the sensor device is operated in two different modes of operation. First and second values (c, c) of the same fluid parameter are determined in the two modes. A fault indicator value (F) is derived by comparing the first and second values. The first mode of operation may be a steady-state mode, the first value (c) being based on a steady-state response of the sensor device to heater power being supplied to the heaters, and the second mode of operation may be a dynamic mode, the second value (c) being based on a transient response.

Fault detection in a thermal sensor device

A thermal sensor comprises an active element (), e.g., a heater or cooler, at least one temperature sensor (), and processing circuitry (). The processing circuitry causes a change of power supplied to the active element (). It then determines, at a plurality of times, a thermal parameter based on an output signal of the temperature sensors and analyzes the transient behavior of the thermal parameter. Based on this analysis, the processing circuitry determines a contamination signal that is indicative of a contamination on a sensing surface of the thermal sensor. If the thermal sensor comprises a plurality of temperature sensors arranged in different sectors of the sensing surface, a multi-sector thermal signal can be derived from the outputs of the sensors, and determination of the contamination signal can be based on the multi-sector thermal signal.

Detection of contaminations on a sensing surface of a thermal sensor

The disclosure concerns a sensor device for determining the thermal capacity of a natural gas. The sensor device comprises a substrate, a recess or opening arranged in the substrate, a first heating component and a first sensing component. The first heating component comprises a first heating structure and a temperature sensor and the first sensing component comprises a temperature sensor. The sensor device is configured to measure the thermal conductivity of the natural gas at a first measuring temperature and at a second measuring temperature. The sensor device is configured to determine a first, in particular a constant, and a second, in particular a linear temperature coefficient of a temperature dependency function of the thermal conductivity and to determine the thermal capacity of the natural gas based on a fitting function. The fitting function is dependent on the first and the second temperature coefficient.

Sensor for determining the thermal capacity of natural gas

A method for determining fluid parameters, such as a heat capacity c&#x3c1;, a calorific value Hp, a methane number MN, and/or a Wobbe index WI, of an unknown fluid (g). An unknown flow () of the fluid (g) is set in a sensor device (), the sensor device () comprising a thermal flow sensor () and a pressure sensor device () for measuring at least one temperature value T, T, a further parameter, and differential pressure value &#x394;&#x3c1; over a flow restrictor (). Using these measurement parameters T, T, &#x394;&#x3c1; and calibration data, the calorific value Hp, and/or the Wobbe index WI, or parameters indicative thereof, of an unknown fluid (g) are calculated. The invention also relates to such a sensor device () and to a computer program product for carrying out such a method.

Determination of fluid parameters

A mass flow controller () comprises a fluid inlet () and at least one first flow meter () to measure a first flow rate (F) and to output a first flow signal (FS); at least one second flow meter () to measure a second flow (F) rate and to output a second flow signal (FS); a control device () connected to said first and second flow meters () and configured and arranged to generate a control signal (C); and at least one control valve () connected to said control device () to control a total flow rate (F) through the mass flow controller () in response to the control signal (C). The control signal (C) is generated as a function of both the first and second flow signals (FS,FS) such that the mass flow controller's () sensitivity to perturbations of said inlet pressure is minimized.

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Stäfa, Switzerland

Andreas Rüegg