Abstract: A duct probe (20) for sampling a fluid from a main fluid flow (Fm) in a duct (10) defines an elongated supply channel (21) n elongated discharge channel (22). The supply channel has at least one inflow opening (23) for diverting a partial flow (Fp) from the main fluid flow into the supply channel, and the discharge channel has at least one outflow opening for returning the partial flow from the discharge channel into the main fluid flow after it has passed an environmental sensor (30). The duct probe further comprises at least one compensation opening (26) that connects the supply channel and the discharge channel in a region that is located between their closed and open ends. By the presence of the compensation opening (26), a jet flow (Fj) is created, which acts to reduce a pressure difference between the supply channel and the discharge channel when the duct probe is exposed to the main fluid flow (Fm).

Abstract: 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 (cstatic, cdynamic) 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 (cstatic) 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 (cstatic) being based on a transient response.

Abstract: A sensor device for determining at least one heat transfer parameter of a gas comprises a sensor unit (10) comprising at least one heater element and at least one temperature sensor. A first (inner) housing (20) receives the sensor unit. The first housing comprises a first membrane (22) allowing a diffusive gas exchange between the exterior and the interior of the first housing. The first housing is received in a second (outer) housing (30). The second housing comprises a second membrane (32) allowing a diffusive gas exchange between the exterior of the second housing and the exterior of the first housing. Thereby temperature gradients inside the first housing are reduced. The second housing can be made of metal and can be disposed on a support plate (40), taking the form of a cap. An auxiliary sensor (50) can be arranged in the space between the first and second housings.

Abstract: 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 (1, 2) comprising first and second temperature sensors (TS1, TS2) and a heater element (31) operable to cause heat transfer to the measurement structures through the gas sample. Processing circuitry provides heating power (P3) 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.

Abstract: A thermal sensor comprises an active element (41), e.g., a heater or cooler, at least one temperature sensor (31), and processing circuitry (50). The processing circuitry causes a change of power supplied to the active element (41). 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.

Abstract: 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.

Abstract: A duct probe (20) for sampling a fluid from a main fluid flow (Fm) in a duct (10) defines an elongated supply channel (21) n elongated discharge channel (22). The supply channel has at least one inflow opening (23) for diverting a partial flow (Fp) from the main fluid flow into the supply channel, and the discharge channel has at least one outflow opening for returning the partial flow from the discharge channel into the main fluid flow after it has passed an environmental sensor (30). The duct probe further comprises at least one compensation opening (26) that connects the supply channel and the discharge channel in a region that is located between their closed and open ends. By the presence of the compensation opening (26), a jet flow (Fj) is created, which acts to reduce a pressure difference between the supply channel and the discharge channel when the duct probe is exposed to the main fluid flow (Fm).

Abstract: 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 (cstatic, cdynamic) 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 (cstatic) 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 (cstatic) being based on a transient response.

Abstract: A method for determining fluid parameters, such as a heat capacity cP?, a calorific value Hp, a methane number MN, and/or a Wobbe index WI, of an unknown fluid (g). An unknown flow (55) of the fluid (g) is set in a sensor device (10), the sensor device (10) comprising a thermal flow sensor (1) and a pressure sensor device (15) for measuring at least one temperature value T1, T2, a further parameter, and differential pressure value ?? over a flow restrictor (14). Using these measurement parameters T1, T2, ?? 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 (10) and to a computer program product for carrying out such a method.

Abstract: A sensor device for determining at least one heat transfer parameter of a gas comprises a sensor unit (10) comprising at least one heater element and at least one temperature sensor. A first (inner) housing (20) receives the sensor unit. The first housing comprises a first membrane (22) allowing a diffusive gas exchange between the exterior and the interior of the first housing. The first housing is received in a second (outer) housing (30). The second housing comprises a second membrane (32) allowing a diffusive gas exchange between the exterior of the second housing and the exterior of the first housing. Thereby temperature gradients inside the first housing are reduced. The second housing can be made of metal and can be disposed on a support plate (40), taking the form of a cap. An auxiliary sensor (50) can be arranged in the space between the first and second housings.

Abstract: A regulation device for regulating a mixing ratio (x) of a gas mixture comprises a first conduit (1) for carrying a flow of a first gas (e.g., air) and a second conduit (2) for carrying a flow of a second gas (e.g., a fuel gas). The first and second conduits (1, 2) open out into a common conduit (3) in a mixing region (M) to form the gas mixture. A first sensor (S1) is configured to determine at least one thermal parameter of the gas mixture downstream from the mixing region. A control device (10) 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 (V1) acting to adjust the mixing ratio, based on the at least one thermal parameter.

Abstract: The disclosure relates to a sensor for detecting and/or analysing a gas. The sensor comprises a substrate, a recess or opening arranged in the substrate, a first bridge structure and a second bridge structure. The first bridge structure and the second bridge structure extend over said recess or opening and are anchored in the substrate. The first bridge structure forms a first hotplate and comprises a first patch of sensing material, in particular of a metal oxide material, arranged on the first hotplate, electrodes adapted to measure an electrical property of the first patch and a heater adapted to heat the first hotplate. The second bridge structure comprises a temperature sensor. The sensor comprises circuitry for driving the heater and for processing signals from the electrodes and the temperature sensor.

Abstract: Method of operating a flow sensor device (10) with a first sensor arrangement (11) for measuring a flow (F) of a fluid (g) and a further first fluid property (p1), and with a second sensor arrangement (12) for measuring a further second fluid property (p2); said method comprising the steps of operating said flow sensor device (10) for determining said further first fluid property (p1) by means of said first sensor arrangement (11), operating said flow sensor device (10) for determining said further second fluid property (p2) by means of said second sensor arrangement (12), comparing said further first fluid property (p1) and further second fluid property (p2) and producing a comparison result (R), and monitoring said comparison result and producing a fault signal (FS) in case of a fault state. The present invention relates to such a sensor device.

Abstract: 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.

Abstract: A thermal sensor comprises an active element (41), e.g., a heater or cooler, at least one temperature sensor (31), and processing circuitry (50). The processing circuitry causes a change of power supplied to the active element (41). 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.

Abstract: The disclosure relates to a sensor for detecting and/or analysing a gas. The sensor comprises a substrate, a recess or opening arranged in the substrate, a first bridge structure and a second bridge structure. The first bridge structure and the second bridge structure extend over said recess or opening and are anchored in the substrate. The first bridge structure forms a first hotplate and comprises a first patch of sensing material, in particular of a metal oxide material, arranged on the first hotplate, electrodes adapted to measure an electrical property of the first patch and a heater adapted to heat the first hotplate. The second bridge structure comprises a temperature sensor. The sensor comprises circuitry for driving the heater and for processing signals from the electrodes and the temperature sensor.

Abstract: A mass flow controller (10) comprises a fluid inlet (15) and at least one first flow meter (11) to measure a first flow rate (F1) and to output a first flow signal (FS1); at least one second flow meter (12) to measure a second flow (F2) rate and to output a second flow signal (FS2); a control device (13) connected to said first and second flow meters (11,12) and configured and arranged to generate a control signal (C); and at least one control valve (14) connected to said control device (13) to control a total flow rate (Fout) through the mass flow controller (10) in response to the control signal (C). The control signal (C) is generated as a function of both the first and second flow signals (FS1,FS2) such that the mass flow controller's (10) sensitivity to perturbations of said inlet pressure is minimized.

Abstract: Method of operating a flow sensor device (10) with a first sensor arrangement (11) for measuring a flow (F) of a fluid (g) and a further first fluid property (p1), and with a second sensor arrangement (12) for measuring a further second fluid property (p2); said method comprising the steps of operating said flow sensor device (10) for determining said further first fluid property (p1) by means of said first sensor arrangement (11), operating said flow sensor device (10) for determining said further second fluid property (p2) by means of said second sensor arrangement (12), comparing said further first fluid property (p1) and further second fluid property (p2) and producing a comparison result (R), and monitoring said comparison result and producing a fault signal (FS) in case of a fault state. The present invention relates to such a sensor device.

Abstract: A flow sensor package comprises a chip comprising a sensitive structure for sensing the flow of a fluid and an encapsulation at least partly encapsulating the chip. A recess in the encapsulation contributes to a flow channel for guiding the fluid, which recess exposes at least the sensitive structure of the chip from the encapsulation, and which recess extends beyond an edge of the chip.

Abstract: A membrane-based thermal flow sensor device with a substrate comprising a cavity, a membrane spanning said cavity and defining a first membrane side and a second membrane side, and a sensitive structure. The sensitive structure is arranged on the membrane and comprises a heater element and a temperature element. The heater element and the temperature element are spaced apart from one another across a first portion of said the membrane. The membrane is provided with one or more through-openings such as to establish a fluid communication between said first and second membrane sides. Furthermore, said one or more through-openings are arranged outside said first portion of said membrane. The present invention also relates to a method of fabrication and to a method of use of said sensor device.