Enhanced offset compensation techniques for thermal conductivity sensing of gas concentration sensors

Abstract

The invention relates to enhanced offset compensation techniques for thermal conductivity sensing of gas concentration sensors. A gas concentration sensor configured to measure a gas concentration of a target gas includes: a reference chamber configured to contain a reference gas; a measurement chamber configured to accommodate a target gas; and a measurement circuit configurable in a calibration mode and an operation mode, comprising a resistive bridge circuit comprising a first resistive element arranged in the reference chamber and a second resistive element arranged in the measurement chamber. The resistive bridge circuit is configured to receive an input voltage and generate a measurement signal based on the input voltage. During the calibration mode, the input voltage has a first voltage value at which the resistive bridge circuit has a negligible sensitivity to the thermal conductivity such that the measurement signal represents an offset. The measurement circuit is configured to subtract the offset from the measurement signal during the mode of operation to generate a compensated measurement signal.

Description

Background Art

[0001] There is an increasing need to reduce oil consumption and switch to green energy. For example, hydrogen generated by wind turbines is considered a possible green fuel for automotive applications.

[0002] Sensors may be needed to detect any leaking hydrogen to avoid the formation of hydrogen and oxygen mixtures. Sensors for measuring gas properties (which may also be referred to as gas sensors) may have cross-sensitivity to different environmental characteristics, such as humidity, temperature and / or the flow and concentration of the gas to be sensed. In some cases, it may be necessary to include dedicated sensors for these additional characteristics in order to distinguish the signals of interest. For example, a complementary temperature sensor may have to be added. This may result in complex devices in which different dies or sensing elements must be combined in a package. Summary of the invention

[0003] In some implementations, a gas concentration sensor configured to sense a gas concentration of a target gas includes: a reference chamber configured to contain a reference gas; a measurement chamber configured to contain a target gas different from the reference gas; and a measurement circuit configurable in a calibration mode and an operation mode, the measurement circuit including: a full-bridge circuit including a first piezoresistive line arranged in the reference chamber and exposed to the reference gas, a second piezoresistive line arranged in the reference chamber and exposed to the reference gas, a third piezoresistive line arranged in the measurement chamber and exposed to the target gas, and a fourth piezoresistive line arranged in the measurement chamber and exposed to the target gas, wherein the full-bridge circuit is configured The method comprises receiving an input voltage and generating a differential signal based on the input voltage, wherein, during a calibration mode, the input voltage has a first voltage value at which the full-bridge circuit has negligible sensitivity to thermal conductivity such that the differential signal represents an offset, wherein, during an operating mode, the input voltage has a second voltage value at which the full-bridge circuit is sensitive to thermal conductivity with an operating sensitivity such that the differential signal represents thermal conductivity of a target gas, wherein the measurement circuit is configured to measure the offset based on the differential signal during the calibration mode, and wherein the measurement circuit is configured to subtract the offset from the differential signal during the operating mode to generate a compensated differential signal.

[0004] In some implementations, a gas concentration sensor configured to sense a gas concentration of a target gas includes: a reference chamber configured to accommodate a reference gas; a measurement chamber configured to accommodate a target gas different from the reference gas; and a measurement circuit configurable in a calibration mode and an operating mode, the measurement circuit including: a resistance bridge circuit including a plurality of resistance elements, the plurality of resistance elements including at least one first resistance element arranged in the reference chamber and at least one second resistance element arranged in the measurement chamber, wherein the resistance bridge circuit is configured to receive an input voltage and generate a measurement signal based on the input voltage, wherein, during the calibration mode, the input voltage has a first voltage value, at which the resistance bridge circuit has a negligible sensitivity to thermal conductivity such that the measurement signal represents an offset, wherein, during the operating mode, the input voltage has a second voltage value, at which the resistance bridge circuit is sensitive to thermal conductivity with an operating sensitivity such that the measurement signal represents the thermal conductivity of the target gas, wherein the measurement circuit is configured to measure the offset based on the measurement signal during the calibration mode, and wherein the measurement circuit is configured to subtract the offset from the measurement signal to generate a compensated measurement signal during the operating mode.

[0005] In some implementations, a method for calibrating an offset of a gas concentration sensor includes: configuring a measurement circuit of the gas concentration sensor in a calibration mode; during the calibration mode, applying a first input voltage to a resistive bridge circuit of the gas concentration sensor so that the resistive bridge circuit generates a first measurement signal, wherein, based on the first input voltage, the resistive bridge circuit has a negligible sensitivity to thermal conductivity, such that the first measurement signal represents an offset; during the calibration mode, configuring a compensation component of the measurement circuit using an offset derived from the first measurement signal; configuring the measurement circuit of the gas concentration sensor in an operating mode; during the operating mode, applying a second input voltage to the resistive bridge circuit of the gas concentration sensor so that the resistive bridge circuit generates a second measurement signal, wherein the second input voltage is greater than the first input voltage, and wherein, based on the second input voltage, the resistive bridge circuit is sensitive to thermal conductivity with an operating sensitivity, such that the second measurement signal represents the thermal conductivity of the measured gas; and during the operating mode, subtracting the offset configured at the compensation component from the second measurement signal to generate a compensated measurement signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Implementations are described herein with reference to the accompanying drawings.

[0007] Figure 1 A gas sensor according to one or more implementations is illustrated.

[0008] Figure 2 A resistive bridge circuit is illustrated in accordance with one or more implementations.

[0009] Figure 3A schematic block diagram of a measurement circuit of a gas sensor according to one or more implementations is illustrated. DETAILED DESCRIPTION

[0010] In the following, details are set forth to provide a more comprehensive explanation of example implementations. However, it will be apparent to those skilled in the art that these implementations may be practiced without these specific details. In other examples, well-known structures and devices are shown in block diagram form or schematic diagrams rather than in detail to avoid confusing the implementations. In addition, unless otherwise specifically mentioned, the features of the different implementations described below may be combined with each other.

[0011] Further, equivalent or similar elements or elements having equivalent or similar functionality are indicated by equivalent or similar reference numerals in the following description. Since identical or functionally equivalent elements are assigned the same reference numerals in the drawings, repeated descriptions of elements provided with the same reference numerals may be omitted. Therefore, the descriptions provided for elements having the same or similar reference numerals are mutually interchangeable.

[0012] The orientation of each element in the accompanying drawings is shown as an example, and the illustrated example can be rotated relative to the depicted orientation. The description provided herein and the subsequent claims relate to any structure having the described relationship between various features, regardless of whether these structures are in the specific orientation of the accompanying drawings, or rotate relative to this orientation. Similarly, spatially related terms (such as "top", "bottom", "below", "below", "lower", "above", "upper", "middle", "left side" and "right side") are used in this article for the convenience of description to describe the relationship between an element and one or more other elements illustrated in the accompanying drawings. In addition to the orientation depicted in the accompanying drawings, spatially relative terms are intended to cover different orientations of elements, structures and / or assemblies in use or operation. Structures and / or assemblies can be oriented (rotated 90 degrees or in other orientations) in other ways, and the spatially relative descriptors used herein can be interpreted accordingly. In addition, in order to simplify the accompanying drawings, unless otherwise indicated, the cross-sectional views in the accompanying drawings only show the features in the plane of the cross section, without showing the material behind the plane of the cross section.

[0013] It is to be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements. Other words used to describe the relationship between elements (e.g., "between" and "directly between," "adjacent to" and "directly adjacent to," etc.) should be interpreted in a similar manner.

[0014] In the implementations described herein or shown in the drawings, any direct electrical connection or coupling (e.g., any connection or coupling without additional intermediate elements) may also be implemented by an indirect connection or coupling (e.g., a connection or coupling with one or more additional intermediate elements, and vice versa), as long as the general purpose of the connection or coupling (e.g., sending a certain signal or sending certain information) is substantially maintained. Features from different implementations may be combined to form other implementations. For example, changes or modifications described with respect to one of the implementations may also apply to other implementations, unless otherwise mentioned.

[0015] As used herein, the terms "substantially" and "approximately" mean "within reasonable tolerances of manufacturing and measurement." For example, the terms "substantially" and "approximately" may be used herein to account for small manufacturing tolerances or other factors (e.g., within 5%) that are considered acceptable in the industry without departing from the various aspects of the implementations described herein. For example, a resistor having an approximate resistance value may actually have a resistance within 5% of the approximate resistance value. As another example, a signal having an approximate signal value may actually have a signal value within 5% of the approximate signal value.

[0016] In the present disclosure, expressions including ordinal numbers (such as "first", "second", etc.) can modify various elements. However, such elements are not limited by such expressions. For example, such expressions do not limit the sequence and / or importance of elements. On the contrary, such expressions are only used for the purpose of distinguishing one element from other elements. For example, the first box and the second box indicate different boxes, although both are boxes. For another example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0017] A "sensor" may refer to a component that converts a characteristic to be measured into an electrical signal (e.g., a current signal or a voltage signal). For example, the characteristic to be measured may include a magnetic field, an electric field, an electromagnetic wave (e.g., a radio wave), a pressure, a force, a current, or a voltage, but is not limited thereto. A gas sensor may measure a characteristic of a gas, such as the thermal conductivity of the gas. Based on the measured characteristic, the presence of the gas may be detected. Additionally, based on the measured characteristic, the concentration of the gas may be measured.

[0018] For example, a gas sensor can measure the thermal conductivity of a target gas by heating four resistor wires connected in a Wheatstone bridge configuration (e.g., a full-bridge resistor circuit), wherein two reference resistor wires are isolated in a stable reference gas and two sensing resistor wires are exposed to a measurement gas, which may include a target gas. By applying a voltage between two input terminals of the Wheatstone bridge configuration, the four resistor wires may experience a temperature change (e.g., a temperature increase). The two reference resistor wires may release heat to a stable reference gas based on the thermal conductivity of the stable reference gas (e.g., the higher the thermal conductivity of the gas, the more heat the gas conducts and releases). In other words, the temperature change of the two reference resistor wires and therefore the resistance change may depend on the heat release rate of heat from the two reference resistor wires to the stable reference gas, which may depend on the thermal conductivity of the stable reference gas. The thermal conductivity of the stable reference gas is a known parameter. The two sensing resistor wires may release heat to the measurement gas based on the thermal conductivity of the measurement gas. In other words, the temperature change of the two sensing resistor wires and therefore the resistance change may depend on the heat release rate of heat from the two sensing resistor wires to the measurement gas, which may depend on the thermal conductivity of the measurement gas. The thermal conductivity of the measurement gas is an unknown parameter. For example, the thermal conductivity of the measurement gas may be related to the concentration of the target gas in the measurement gas.

[0019] The gas sensor can be configured to measure a differential signal output from a Wheatstone bridge configuration. The differential signal can represent a change in resistance of the sensing resistance wire compared to a change in resistance of the reference resistance wire generated by different heat release rates from the four resistance wires to the measuring gas and the stable reference gas, respectively. Therefore, the concentration of the target gas can be measured based on the differential signal.

[0020] The differential signal used to measure the concentration of the target gas may be significantly smaller than the offset generated by external influences such as ambient temperature, ambient pressure, production spread and lifetime drift of the gas sensor. The offset may make it difficult for the gas sensor to obtain useful information from the differential signal. Therefore, the offset should be rejected in order to obtain useful information from the differential signal.

[0021] In some cases, offset compensation can be performed in the digital domain by implementing a compensation polynomial function that accounts for all offset factors, or by inferring the offset directly from reading the gas sensor by applying a nominal voltage and performing a reading before the four resistor wires are heated. However, both of these approaches performed in the digital domain present a problem by imposing a very wide dynamic range on the entire analog signal path of the gas sensor. The dynamic range is the range of variables over which external influences may vary. For example, the dynamic range of ambient temperature may include all ambient temperatures in which a gas sensor may have to operate (e.g., -20° to over 100°F). Similarly, the dynamic range of ambient temperature may include all ambient pressures in which a gas sensor may have to operate. When compensating for offset, the dynamic range of each external influence should be considered. Moreover, the compensation polynomial function is complex, requires a lot of processing power, and may not accurately account for all offset factors within the corresponding dynamic range.

[0022] Some implementations disclosed herein relate to reducing the impact of the offset amplitude on the downstream signal path by performing an initial offset compensation measurement as an initial compensation step. The initial offset compensation measurement can be performed by applying a low input supply voltage (e.g., about 1V) between two input terminals of a resistive bridge circuit (e.g., a Wheatstone bridge configuration) and reading a measurement signal (e.g., a differential signal) of the resistive bridge circuit when the low input supply voltage is applied. During the initial offset compensation measurement, the sensitivity of the resistive bridge circuit to thermal conductivity may be zero or close to zero, while non-gas offset effects (e.g., external influences such as ambient temperature, ambient pressure, production diffusion and lifetime drift of the gas sensor) are still measurable. Therefore, the non-gas offset effect can be isolated from the thermal conductivity sensitivity of the gas sensor. Therefore, during the initial offset compensation measurement, the non-gas offset effect can be measured independently of the thermal conductivity sensitivity of the gas sensor to obtain accurate measurements of all non-gas offset effects in a single measurement without considering each corresponding dynamic range of the non-gas offset effect. In other words, a single offset that takes into account all non-gas offset effects can be measured. Therefore, the complexity of considering all non-gas offset effects for offset compensation can be reduced. Therefore, the processing power of the gas sensor can also be reduced.

[0023] In addition, since the amplitude of the measurement signal at the output of the resistance bridge circuit is proportional to the input power supply voltage, the amplitude of the offset can be reduced by using a low input power supply voltage, which can relax the signal processing requirements for the analog signal path of the gas sensor. In other words, the processing components arranged on the analog signal path can be simplified, which can reduce the complexity and manufacturing cost of the gas sensor.

[0024] The offset measured during the initial offset compensation measurement can then be scaled according to the scaling factor, then fed back to the analog signal path, and subtracted from the measurement signal generated during the operating mode of the gas sensor. Therefore, the measurement signal generated during the operating mode of the gas sensor can be compensated by the offset measured during the initial offset compensation measurement. The scaling factor can be determined based on the ratio of the input power supply voltage (e.g., 5V) used during the operating mode and the low input power supply voltage (e.g., 1V) used during the initial offset compensation measurement. For example, when the input power supply voltage used during the operating mode is 5V and the low input power supply voltage used during the initial offset compensation measurement is 1V, the scaling factor can be 5. By subtracting the offset from the measurement signal during the operating mode, the residual offset output from the analog signal path is significantly smaller, which can be more easily compensated by other techniques in the digital domain. Since the residual offset is much smaller than the residual offset present at the output of the analog signal path, the signal processing requirements for the digital signal path can be relaxed, which can lead to reduced processing power, reduced complexity, and reduced manufacturing costs for the gas sensor.

[0025] Figure 1 A gas sensor 100 according to one or more implementations is illustrated. The gas sensor 100 may be a thermal conductivity (TC) sensor that measures the concentration of a target gas contained in a measurement gas using a known thermal conductivity of a reference gas. For example, the gas sensor 100 may be configured to measure the thermal conductivity of the measurement gas based on a measurement signal, and determine the concentration of the target gas based on the thermal conductivity of the measurement gas.

[0026] The gas sensor 100 may include a housing 102 or a casing including a reference chamber 104 configured to hold a reference gas and a measurement chamber 106 configured to hold a measurement gas (e.g., an ambient gas) different from the reference gas. The reference gas may be oxygen or nitrogen, but is not limited thereto. In some implementations, the reference gas may be a vacuum gas. The measurement gas may be a target gas or may include a target gas. There may be no target gas in the reference gas. The reference chamber 104 may be a sealed chamber. For example, in some implementations, the reference chamber 104 may be gas-sealed. In addition, the housing 102 may have an opening 108 (e.g., a conduit) that allows the measurement gas to enter the measurement chamber 106. Thus, the opening 108 may be provided for fluidly connecting the measurement chamber 106 to the measurement gas.

[0027] The gas sensor 100 may include a plurality of resistive elements, such as piezoresistive wires. When the gas sensor 100 is in an off state (e.g., when an input power supply voltage is not applied to the plurality of resistive elements), the resistivities of the plurality of resistive elements may be substantially the same. In some implementations, the gas sensor 100 may include a first piezoresistive wire 110, a second piezoresistive wire 112, a third piezoresistive wire 114, and a fourth piezoresistive wire 116. The first piezoresistive wire 110 may be disposed in a reference chamber 104 and may be exposed to a reference gas, the second piezoresistive wire 112 may be disposed in a reference chamber 104 and may be exposed to a reference gas, the third piezoresistive wire 114 may be disposed in a measurement chamber 106 and may be exposed to a measurement gas, and the fourth piezoresistive wire 116 may be disposed in a measurement chamber 106 and may be exposed to a measurement gas.

[0028] A plurality of resistor elements may be provided in a resistor bridge circuit, such as a full bridge circuit (e.g., a Wheatstone bridge). In other words, a plurality of resistor elements may be connected in a full bridge configuration, the full bridge configuration including two input terminals to which an input voltage is applied and two output terminals from which a differential signal (e.g., a differential voltage) is output as a measurement signal. In other words, the full bridge circuit may be configured to receive an input voltage and generate a differential signal at a differential output of the resistor bridge circuit based on the input voltage. The first piezoresistance line 110 and the second piezoresistance line 112 may be arranged on opposite segments of the full bridge circuit. For example, the full bridge circuit may include two half bridges, including a first half bridge and a second half bridge. The first piezoresistance line 110 may be arranged in a first half bridge, and the second piezoresistance line 112 may be arranged in a second half bridge. The first piezoresistance line 110 may be arranged diagonally with the second piezoresistance line 112. The third piezoresistance line 114 and the fourth piezoresistance line 116 may also be arranged on opposite segments of the full bridge circuit. For example, the third piezoresistive line 114 may be arranged in the first half bridge and the fourth piezoresistive line 116 may be arranged in the second half bridge. The third piezoresistive line 114 may be arranged diagonally to the fourth piezoresistive line 116. Thus, each half bridge is formed by one measuring piezoresistive line and one reference piezoresistive line.

[0029] In some implementations, only a single half-bridge may be used. For example, the plurality of resistive elements may include only two resistance lines. In this case, the resistance bridge circuit may, for example, include only a first piezoresistive line 110 and a third piezoresistive line 114. The single half-bridge may be configured to output a measurement signal from an output node arranged and coupled between the two resistance lines. The measurement signal may represent a change in resistance of the first piezoresistive line 110 compared to a change in resistance of the third piezoresistive line 114, which are generated by different heat release rates from the two resistance lines to the measurement gas and the reference gas, respectively. Therefore, the concentration of the target gas may be measured based on the measurement signal.

[0030] As indicated above, Figure 1 are provided as examples. Other examples may differ from those regarding Figure 1 as described. Figure 1 The number and arrangement of devices and components shown are provided as examples. Figure 1 There may be additional devices or components, fewer devices or components, different devices or components, or devices or components arranged differently than those shown.

[0031] Figure 2 A resistive bridge circuit 200 according to one or more implementations is illustrated. The resistive bridge circuit 200 may include a first piezoresistive line 110, a second piezoresistive line 112, a third piezoresistive line 114, and a fourth piezoresistive line 116 connected in a full-bridge configuration. The resistive bridge circuit 200 includes a first half-bridge on the left and a second half-bridge on the right. The first piezoresistive line 110 may be arranged in the first half-bridge, and the second piezoresistive line 112 may be arranged in the second half-bridge. The first piezoresistive line 110 may be arranged diagonally with the second piezoresistive line 112. The third piezoresistive line 114 and the fourth piezoresistive line 116 may also be arranged on opposite segments of the full-bridge circuit. For example, the third piezoresistive line 114 may be arranged in the first half-bridge, and the fourth piezoresistive line 116 may be arranged in the second half-bridge. The third piezoresistive line 114 may be arranged diagonally with the fourth piezoresistive line 116. Therefore, each half-bridge is formed by a measuring piezoresistive line and a reference piezoresistive line.

[0032] The resistance bridge circuit 200 may include two input terminals, including a first input terminal 201 and a second input terminal 202. An input voltage Vin may be applied to the first input terminal 201 and the second input terminal 202. In other words, the input voltage Vin is applied between the two input terminals. The voltage level of the input voltage Vin may be controlled by a controller. The resistance bridge circuit 200 may also include two output terminals, including a first output terminal 203 and a second output terminal 204. Applying the input voltage Vin to the two input terminals causes the resistance bridge circuit 200 to generate a differential signal Vout (e.g., an output voltage) at the two output terminals. The differential signal Vout may be measured between the two output terminals and may be used as a measurement signal by the gas sensor 100.

[0033] The differential signal Vout may depend on the voltage level of the input voltage Vin and the corresponding resistances of the first piezoresistive line 110, the second piezoresistive line 112, the third piezoresistive line 114, and the fourth piezoresistive line 116. For example, by applying or increasing the input voltage Vin between the two input terminals 201 and 202 of the resistor bridge circuit 200, the first piezoresistive line 110, the second piezoresistive line 112, the third piezoresistive line 114, and the fourth piezoresistive line 116 may experience a temperature change (e.g., a temperature increase). Alternatively, the piezoresistive lines 110, 112, 114, and 116 may experience a temperature decrease by reducing the input voltage Vin or removing the input voltage Vin.

[0034] When the input voltage Vin is applied (e.g., from an off state) or the input voltage Vin is increased, the piezoresistive wires 110, 112, 114, and 116 may heat up depending on the voltage level of the input voltage Vin. Based on the exposure of the first and second piezoresistive wires 110, 112 to the reference gas and based on the exposure of the third and fourth piezoresistive wires 114, 116 to the measurement gas, the temperature changes of the piezoresistive wires 110, 112, 114, and 116 may occur at different rates.

[0035] For example, the first piezoresistive wire 110 and the second piezoresistive wire 112 may release heat to the reference gas based on the thermal conductivity of the reference gas. In other words, the temperature change of the first piezoresistive wire 110 and the second piezoresistive wire 112 and therefore the resistance change may depend on the heat release rate of the heat from the first piezoresistive wire 110 and the second piezoresistive wire 112 to the reference gas, which may depend on the thermal conductivity of the reference gas.

[0036] The third piezoresistive wire 114 and the fourth piezoresistive wire 116 may release heat to the measurement gas based on the thermal conductivity of the measurement gas. In other words, the temperature change and therefore the resistance change of the third piezoresistive wire 114 and the fourth piezoresistive wire 116 may depend on the heat release rate of the heat from the third piezoresistive wire 114 and the fourth piezoresistive wire 116 to the measurement gas, which may depend on the thermal conductivity of the measurement gas, which may be related to the concentration of the target gas in the measurement gas.

[0037] The gas sensor 100 may be configured to measure a differential signal Vout output from the resistance bridge circuit 200. The differential signal Vout may represent resistance changes of the third piezoresistive line 114 and the fourth piezoresistive line 116 relative to resistance changes of the first piezoresistive line 110 and the second piezoresistive line 112, which are generated by different heat release rates from the piezoresistive lines to the measurement gas and the reference gas, respectively. Therefore, the concentration of the target gas may be measured based on the differential signal Vout.

[0038] As indicated above, Figure 2 are provided as examples. Other examples may differ from those regarding Figure 2as described.

[0039] Figure 3 FIG. 3 is a schematic block diagram of a measurement circuit 300 of a gas concentration sensor according to one or more implementations. The measurement circuit 300 may be implemented as a combination of Figure 1 and 2 A portion of the gas sensor described herein. For example, the measurement circuit 300 may include piezoresistive lines 110, 112, 114, and 116 arranged in the resistance bridge circuit 200. In addition, the measurement circuit 300 may include a controller 302, a subtractor 304 (e.g., a subtractor component) arranged on an analog signal path, an analog-to-digital converter (ADC) 306, a scaler 308 (e.g., a multiplier), an offset digital-to-analog converter (DAC) 310, and a digital signal processing circuit 312. The scaler 308 and the offset DAC 310 may be arranged in a compensation feedback path.

[0040] The controller 302 may be a power supply voltage controller that may be configured to control the voltage level of the input voltage Vin. For example, the measurement circuit 300 may be configurable in a calibration mode and an operating mode. During the calibration mode, the measurement circuit 300 may be configured to measure an offset that takes into account one or more non-gas offset effects. During the operating mode, the measurement circuit 300 may be configured to measure the concentration of a target gas that may be present in the measurement gas. During the operating mode, the measurement circuit 300 may compensate the differential signal Vout output from the resistance bridge circuit 200 based on the offset measured during the calibration mode to generate a compensated differential signal Vout'.

[0041] During the calibration mode, the controller 302 may control the input voltage Vin so that the input voltage Vin has a first voltage value, at which the resistance bridge circuit 200 has negligible sensitivity to thermal conductivity, so that the differential signal Vout represents an offset (e.g., an offset value). In other words, at the first voltage value, the piezoresistive lines 110, 112, 114, and 116 may be substantially insensitive to thermal conductivity and may be primarily sensitive to non-gas offset effects. Therefore, during the calibration mode, the differential signal Vout may be sensitive to non-gas offset effects and may not be affected (e.g., to a measurable extent) by the thermal conductivity of the measurement gas and the thermal conductivity of the reference gas. In contrast, during the operating mode, the controller 302 may control the input voltage Vin so that the input voltage Vin has a second voltage value, at which the resistance bridge circuit 200 is sensitive to thermal conductivity with an operating sensitivity, so that the differential signal Vout represents the thermal conductivity of the measurement gas (e.g., a target gas). In other words, at the second voltage value, the piezoresistive lines 110, 112, 114, and 116 may be sensitive to the thermal conductivity of the measurement gas and the thermal conductivity of the reference gas. Therefore, during the operating mode, the differential signal Vout may be affected by the thermal conductivity of the measurement gas. Therefore, by configuring the measurement circuit 300 in the calibration mode, the offset caused by the non-gas offset effect can be isolated from the thermal conductivity and used to compensate the differential signal Vout during the operating mode.

[0042] The measurement circuit 300 can be configured to measure the offset based on the differential signal Vout during the calibration mode, and to subtract the offset (e.g., the offset value) from the differential signal Vout during the operational description to generate a compensated differential signal Vout'. Therefore, during the operational mode, the compensated differential signal Vout' can be a more accurate representation of the thermal conductivity of the measurement gas (e.g., the target gas) compared to the differential signal Vout.

[0043] The first voltage value is less than the second voltage value. For example, in some implementations, the first voltage value may be less than 1.5V, and the second voltage value may be greater than 3.5V. The first voltage value may be set so that the negligible sensitivity to thermal conductivity is at least two orders of magnitude smaller than the operational sensitivity to thermal conductivity. In other words, the sensitivity of the piezoresistive lines 110, 112, 114, and 116 to thermal conductivity during the calibration mode may be at least 100 times smaller than during the operational mode.

[0044] During the calibration mode, the input voltage Vin may cause the first piezoresistive line 110, the second piezoresistive line 112, the third piezoresistive line 114, and the fourth piezoresistive line 116 to experience a negligible temperature change, such that the differential signal Vout is a measure of at least one offset effect (e.g., at least one non-gas offset effect, such as pressure, temperature, production diffusion, or lifetime drift). For example, during the calibration mode, the input voltage Vin may cause the first piezoresistive line 110 and the second piezoresistive line 112 to experience a first resistance change based on the at least one offset effect, and may cause the third piezoresistive line 114 and the fourth piezoresistive line 116 to experience a second resistance change based on the at least one offset effect.

[0045] During the operation mode, the input voltage Vin may cause the first piezoresistive wire 110 and the second piezoresistive wire 112 to experience a first temperature increase based on a first heat release rate to the reference gas, and may cause the third piezoresistive wire 114 and the fourth piezoresistive wire 116 to experience a second temperature increase based on a second heat release rate to the target gas. For example, during the operation mode, the input voltage Vin may cause the first piezoresistive wire 110 and the second piezoresistive wire 112 to experience a third resistance change based on a first thermal interaction of the first piezoresistive wire 110 and the second piezoresistive wire 112 with the reference gas. Additionally, during the operation mode, the input voltage Vin causes the third piezoresistive wire 114 and the fourth piezoresistive wire 116 to experience a fourth resistance change based on a second thermal interaction of the third piezoresistive wire 114 and the fourth piezoresistive wire 116 with the measurement gas (e.g., the target gas). In other words, during the operating mode, the input voltage Vin can cause the first piezoresistive line 110 and the second piezoresistive line 112 to experience a third resistance change based on the thermal conductivity of the reference gas, and can cause the third piezoresistive line 114 and the fourth piezoresistive line 116 to experience a fourth resistance change based on the thermal conductivity of the target gas (e.g., the target gas).

[0046] The subtractor 304 may be configured to receive the differential signal Vout from the resistive bridge circuit 200. During the calibration mode, the offset DAC 310 may not provide an analog offset signal to the subtractor 304 (e.g., the output of the offset DAC 310 may be disabled or set to zero). Therefore, during the calibration mode, the differential signal Vout may pass through the subtractor 304 unchanged. In other words, during the calibration mode, the subtractor 304 may output the differential signal Vout to the ADC 306. During the operating mode, the offset DAC 310 may provide an analog offset signal having an offset value determined during the calibration mode, and the subtractor 304 may subtract the offset value from the differential signal Vout to generate a compensated differential signal Vout'.

[0047] ADC 306 is coupled to the output of subtractor 304. During calibration mode, ADC 306 may generate a digital signal Dout based on the differential signal Vout provided by subtractor 304. For example, ADC 306 may convert the differential signal Vout into a digital signal Dout. Based on the ratio of the second voltage value to the first voltage value, the digital signal Dout is proportional to the offset. Therefore, during calibration mode, scaler 308 may amplify or multiply the digital signal Dout by a scaling factor to generate a scaled digital signal Dx, which is equal to the offset (e.g., equal to the offset value to be applied to subtractor 304 during operation mode). The scaling factor may be equal to the ratio of the second voltage value to the first voltage value. For example, if the second voltage value is 5V and the first voltage value is 1V, the scaling factor is 5. Therefore, the scaled digital signal Dx may be 5 times larger than the digital signal Dout. Offset DAC 310 may receive the scaled digital signal Dx and generate an analog offset signal based on the scaled digital signal Dx. For example, during the calibration mode, the offset DAC 310 may convert the scaled digital signal Dx into an analog value and store the analog value as an offset value to be used during the operation mode. During the operation mode, the offset DAC 310 may output an analog offset signal having a stored offset value, which is to be subtracted from the differential signal by the subtractor 304. Therefore, during the operation mode, the subtractor 304 may generate a compensated differential signal Vout' by subtracting the offset value from the differential signal Vout to perform offset compensation. Finally, during the operation mode, the ADC 306 may convert the compensated differential signal Vout' into a digital measurement signal Dout, which represents the thermal conductivity of the measurement gas (e.g., the target gas). The ADC 306 may provide the digital measurement signal Dout to the digital signal processing circuit 312 for further digital processing.

[0048] Thus, a single offset that takes into account one or more (eg, all) non-gas offset effects may be measured during the calibration mode. Thus, the complexity of taking into account all non-gas offset effects for offset compensation may be reduced. Thus, the processing power of the gas sensor may also be reduced.

[0049] In addition, since the amplitude of the differential signal Vout is proportional to the input power supply voltage, the use of a low input voltage can reduce the amplitude of the offset, which can relax the signal processing requirements for the analog signal path of the gas sensor 100. In other words, the processing components arranged on the analog signal path can be simplified, which can reduce the complexity and manufacturing cost of the gas sensor 100. Moreover, by subtracting the offset from the differential signal Vout during the operating mode, a significantly smaller residual offset is output from the analog signal path, which can be more easily compensated by other techniques in the digital domain. Since the residual offset is much smaller than the residual offset present at the output of the analog signal path, the signal processing requirements for the digital signal path of the digital signal processing circuit 312 can be relaxed, which can cause the processing power of the digital signal processing circuit 312 to be reduced, the complexity to be reduced, and the manufacturing cost to be reduced.

[0050] As indicated above, Figure 3 are provided as examples. Other examples may differ from those regarding Figure 3 as described. Figure 3 The number and arrangement of devices and components shown are provided as examples. Figure 3 There may be additional devices or components, fewer devices or components, different devices or components, or devices or components arranged differently than those shown.

[0051] The following provides an overview of some aspects of the disclosure:

[0052] Aspect 1: A gas concentration sensor configured to measure a gas concentration of a target gas, comprising: a reference chamber configured to contain a reference gas; a measuring chamber configured to contain a target gas different from the reference gas; and a measuring circuit configurable in a calibration mode and an operating mode, the measuring circuit comprising: a full-bridge circuit comprising a first piezoresistive line arranged in the reference chamber and exposed to the reference gas, a second piezoresistive line arranged in the reference chamber and exposed to the reference gas, a third piezoresistive line arranged in the measuring chamber and exposed to the target gas, and a fourth piezoresistive line arranged in the measuring chamber and exposed to the target gas, wherein the full-bridge circuit is configured to connect The measuring circuit receives an input voltage and generates a differential signal based on the input voltage, wherein, during a calibration mode, the input voltage has a first voltage value, at which the full-bridge circuit has negligible sensitivity to thermal conductivity, such that the differential signal represents an offset, wherein, during an operating mode, the input voltage has a second voltage value, at which the full-bridge circuit is sensitive to thermal conductivity with an operating sensitivity, such that the differential signal represents thermal conductivity of a target gas, wherein the measuring circuit is configured to measure the offset based on the differential signal during the calibration mode, and wherein the measuring circuit is configured to subtract the offset from the differential signal during the operating mode to generate a compensated differential signal.

[0053] Aspect 2: The gas concentration sensor of aspect 1, wherein, during the operating mode, the compensated differential signal is a more accurate representation of the thermal conductivity of the target gas than the differential signal.

[0054] Aspect 3: The gas concentration sensor according to any one of aspects 1 to 2, wherein the first voltage value is smaller than the second voltage value.

[0055] Aspect 4: The gas concentration sensor according to any one of aspects 1 to 3, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude smaller than the operational sensitivity to thermal conductivity.

[0056] Aspect 5: A gas concentration sensor according to any one of Aspects 1 to 4, wherein during the calibration mode, the input voltage causes the first piezoresistive line, the second piezoresistive line, the third piezoresistive line and the fourth piezoresistive line to experience negligible temperature changes, so that the differential signal is a measure of at least one offset effect.

[0057] Aspect 6: The gas concentration sensor of aspect 5, wherein the at least one offset effect comprises at least one of pressure, temperature, production diffusion, or lifetime drift.

[0058] Aspect 7: A gas concentration sensor according to Aspect 5, wherein, during an operating mode, an input voltage causes the first piezoresistive line and the second piezoresistive line to experience a first temperature increase based on a first heat release rate to a reference gas, and wherein, during an operating mode, an input voltage causes the third piezoresistive line and the fourth piezoresistive line to experience a second temperature increase based on a second heat release rate to a target gas.

[0059] Aspect 8: A gas concentration sensor according to any one of Aspects 1 to 7, wherein the measurement circuit further includes: a subtractor component configured to receive a differential signal, wherein the subtractor component is configured to output a differential signal during a calibration mode, and wherein the subtractor component is configured to subtract an offset from the differential signal during an operating mode to generate a compensated differential signal.

[0060] Aspect 9: A gas concentration sensor according to Aspect 8, wherein the measurement circuit further includes: an ADC coupled to the output of the subtractor component, wherein the ADC is configured to generate a digital signal based on the differential signal during a calibration mode; a scaler configured to amplify the digital signal by a scaling factor during the calibration mode to generate a scaled digital signal equal to the offset, wherein the scaling factor is equal to the ratio of the second voltage value to the first voltage value; and a DAC configured to receive the scaled digital signal and generate an analog offset signal based on the scaled digital signal.

[0061] Aspect 10: The gas concentration sensor according to aspect 9, wherein the DAC is configured to provide an analog offset signal to the subtractor component during the operating mode, and wherein the subtractor component is configured to subtract the analog offset signal from the differential signal to generate a compensated differential signal during the operating mode.

[0062] Aspect 11: The gas concentration sensor of Aspect 9, wherein the ADC is configured to convert the compensated differential signal into a digital measurement signal during the operating mode, the digital measurement signal representing the thermal conductivity of the target gas.

[0063] Aspect 12: A gas concentration sensor configured to measure the gas concentration of a target gas, comprising: a reference chamber configured to accommodate a reference gas; a measuring chamber configured to accommodate a target gas different from the reference gas; and a measurement circuit configurable in a calibration mode and an operating mode, the measurement circuit comprising: a resistance bridge circuit comprising a plurality of resistance elements, the plurality of resistance elements comprising at least one first resistance element arranged in the reference chamber and at least one second resistance element arranged in the measuring chamber, wherein the resistance bridge circuit is configured to receive an input voltage and generate a measurement signal based on the input voltage, wherein, during the calibration mode, the input voltage has a first voltage value, at the first voltage value, the resistance bridge circuit has a negligible sensitivity to thermal conductivity, so that the measurement signal represents an offset, wherein, during the operating mode, the input voltage has a second voltage value, at the second voltage value, the resistance bridge circuit is sensitive to thermal conductivity with an operating sensitivity, so that the measurement signal represents the thermal conductivity of the target gas, wherein the measurement circuit is configured to measure the offset based on the measurement signal during the calibration mode, and wherein the measurement circuit is configured to subtract the offset from the measurement signal during the operating mode to generate a compensated measurement signal.

[0064] Aspect 13: The gas concentration sensor of aspect 12, wherein, during the operating mode, the compensated measurement signal is a more accurate representation of the thermal conductivity of the target gas than the measurement signal.

[0065] Aspect 14: The gas concentration sensor according to any one of Aspects 12 to 13, wherein the first voltage value is smaller than the second voltage value.

[0066] Aspect 15: The gas concentration sensor of any one of Aspects 12 to 14, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude less than the operational sensitivity to thermal conductivity.

[0067] Aspect 16: A gas concentration sensor according to any one of Aspects 12 to 15, wherein, during a calibration mode, an input voltage causes at least one first resistor element to undergo a first resistance change based on at least one offset effect, and wherein, during a calibration mode, an input voltage causes at least one second resistor element to undergo a second resistance change based on at least one offset effect.

[0068] Aspect 17: A gas concentration sensor according to Aspect 16, wherein, during an operating mode, an input voltage causes at least one first resistor element to undergo a third resistance change based on a first thermal interaction between the at least one first resistor element and a reference gas, and wherein, during an operating mode, an input voltage causes at least one second resistor element to undergo a fourth resistance change based on a second thermal interaction between the at least one second resistor element and a target gas.

[0069] Aspect 18: A gas concentration sensor according to Aspect 16, wherein, during an operating mode, an input voltage causes at least one first resistor element to undergo a third resistance change based on the thermal conductivity of a reference gas, and wherein, during an operating mode, an input voltage causes at least one second resistor element to undergo a fourth resistance change based on the thermal conductivity of a target gas.

[0070] Aspect 19: A method for calibrating an offset of a gas concentration sensor, the method comprising: configuring a measurement circuit of the gas concentration sensor in a calibration mode; during the calibration mode, applying a first input voltage to a resistive bridge circuit of the gas concentration sensor so that the resistive bridge circuit generates a first measurement signal, wherein, based on the first input voltage, the resistive bridge circuit has a negligible sensitivity to thermal conductivity, so that the first measurement signal represents an offset; during the calibration mode, configuring a compensation component of the measurement circuit using the offset derived from the first measurement signal; configuring the measurement circuit of the gas concentration sensor in an operating mode; during the operating mode, applying a second input voltage to the resistive bridge circuit of the gas concentration sensor so that the resistive bridge circuit generates a second measurement signal, wherein the second input voltage is greater than the first input voltage, and wherein, based on the second input voltage, the resistive bridge circuit is sensitive to thermal conductivity with an operating sensitivity, so that the second measurement signal represents the thermal conductivity of the measured gas; and during the operating mode, subtracting the offset configured at the compensation component from the second measurement signal to generate a compensated measurement signal.

[0071] Aspect 20: The method of aspect 19, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude less than the operational sensitivity to thermal conductivity.

[0072] Aspect 21: A system configured to perform one or more operations listed in one or more of aspects 1 to 20.

[0073] Aspect 22: An apparatus comprising means for performing one or more operations recited in one or more of Aspects 1 to 20.

[0074] Aspect 23: A non-transitory computer-readable medium storing an instruction set, the instruction set comprising one or more instructions, which, when executed by a device, causes the device to perform one or more operations listed in one or more of aspects 1 to 20.

[0075] Aspect 24: A computer program product comprising instructions or codes for performing one or more operations recited in one or more of Aspects 1 to 20.

[0076] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementations to the precise forms disclosed.Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations.

[0077] Some implementations may be described herein in conjunction with a threshold value. As used herein, "satisfying" a threshold value may refer to a value being greater than a threshold value, more than a threshold value, above a threshold value, greater than or equal to a threshold value, less than a threshold value, less than a threshold value, below a threshold value, less than or equal to a threshold value, equal to a threshold value, etc.

[0078] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or a combination of hardware and software. It will be apparent that the systems and / or methods described herein may be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit the implementation. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code - it is to be understood that software and hardware can be designed to implement the systems and / or methods based on the description herein.

[0079] Any processing unit can be implemented as a central processing unit (CPU) or other processor, reading and executing software programs from non-transient computer-readable recording media such as hard disks or semiconductor memory devices. For example, instructions can be executed by one or more processors, such as one or more CPUs, digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), programmable logic controllers (PLCs), or other equivalent integrated or discrete logic circuit systems. Therefore, the term "processor" used herein refers to any of the aforementioned structures or any other structure suitable for implementing the technology described herein. Software can be stored on a non-transient computer-readable medium, so that the non-transient computer-readable medium includes a program code or a program algorithm stored thereon, which causes the processor to perform the steps of the method via a computer program when executed.

[0080] A controller including hardware may also perform one or more techniques of the present disclosure. A controller including one or more processors may use electrical signals and digital algorithms to perform its receiving, analyzing, and controlling functions, which may also include correction functions. Such hardware, software, and firmware may be implemented in the same device or in separate devices to support the various techniques described in the present disclosure.

[0081] Signal processing circuitry and / or signal conditioning circuitry may receive one or more signals (e.g., measurement signals) from one or more components in the form of raw measurement data, and may derive further information from the measurement signals. As used herein, signal conditioning refers to manipulating an analog signal so that the signal meets the requirements of the next stage for further processing. Signal conditioning may include conversion from analog to digital (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range matching, isolation, and any other process required to make the signal suitable for processing after conditioning.

[0082] Even if the specific combination of features is listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the implementation described herein. Many of these features can be combined in a manner that is not specifically listed in the claims and / or disclosed in the specification. For example, the present disclosure includes each dependent claim in the claim set and each other single claim combination in the claim set and each combination of multiple claims in the claim set. As used herein, the phrase "at least one of" the referenced item list refers to any combination of these items, including a single member. As an example, "at least one of the following: a, b or c" is intended to cover a, b, c, a+b, a+c, b+c and a+b+c and any combination with multiple identical items (e.g., a+a, a+a+a, a+a+b, a+a+c, a+b+b, a+c+c, b+b, b+b+b, b+b+c, c+c and c+c+c or any other ordering of a, b and c).

[0083] Further, it is to be understood that the disclosure of multiple actions or functions disclosed in the specification or claims may not be construed as being in a specific order. Therefore, the disclosure of multiple actions or functions does not restrict these to a specific order unless such actions or functions are not interchangeable for technical reasons. In addition, in some implementations, a single action may include or may be decomposed into multiple sub-actions. Unless explicitly excluded, such sub-actions may be included and be part of the disclosure of the single action.

[0084] When a "component" or "one or more components" (or another element, such as a "controller" or "one or more controllers") is described or claimed (either within a single claim or across multiple claims) as performing or being configured to perform multiple operations, such language is intended to broadly cover a variety of architectures and environments. For example, unless otherwise expressly claimed (e.g., via the use of "a first component" and "a second component" or other language that distinguishes components in a claim), the language is intended to cover a single component that performs or is configured to perform all operations, a group of components that collectively perform or are configured to perform all operations, a first component that performs or is configured to perform a first operation and a second component that performs or is configured to perform a second operation, or any combination of components that perform or are configured to perform these operations. For example, when a claim is of the form "one or more components are configured to: perform X; perform Y; and perform Z," the claim should be interpreted to mean "one or more components are configured to perform X; one or more (possibly different) components are configured to perform Y; and one or more (possibly different) components are configured to perform Z."

[0085] Unless explicitly described as such, the elements, actions or instructions used herein should not be interpreted as critical or necessary. Moreover, as used herein, the articles "one" and "an" are intended to include one or more items and can be used interchangeably with "one or more". Further, as used herein, the article "the" is intended to include one or more items quoted in conjunction with the article "the", and can be used interchangeably with "one or more". In the case of meaning only one item, the phrases "only one", "single" or similar language are used. Moreover, as used herein, the terms "has", "have", "having" etc. are intended to be open terms, without limiting the elements they modify (e.g., element "has" A may also have B). Further, unless otherwise expressly stated, the phrase "based on" is intended to mean "based at least in part". As used herein, the term "multiple" can be replaced with "a plurality of", and vice versa. Furthermore, as used herein, the term "or" when used in tandem is intended to be inclusive and may be used interchangeably with "and / or" unless expressly stated otherwise (eg, if used in combination with "either" or "only one of...").

Claims

1. A gas concentration sensor configured to measure the gas concentration of a target gas, the gas concentration sensor comprising: a reference chamber configured to contain a reference gas; a measurement chamber configured to contain a target gas different from the reference gas; as well as A measurement circuit is configurable in a calibration mode and an operation mode, the measurement circuit comprising: A full-bridge circuit, comprising: a first piezoresistive line arranged in the reference chamber and exposed to the reference gas; a second piezoresistive line arranged in the reference chamber and exposed to the reference gas; a third piezoresistive line arranged in the measurement chamber and exposed to the target gas; and a fourth piezoresistive line arranged in the measurement chamber and exposed to the target gas, wherein the full bridge circuit is configured to receive an input voltage and generate a differential signal based on the input voltage, wherein, during the calibration mode, the input voltage has a first voltage value at which the full-bridge circuit has a negligible sensitivity to thermal conductivity such that the differential signal represents an offset, wherein during the operating mode, the input voltage has a second voltage value at which the full bridge circuit is sensitive to thermal conductivity with an operating sensitivity such that the differential signal represents the thermal conductivity of the target gas, wherein the measurement circuit is configured to measure the offset based on the differential signal during the calibration mode, and Wherein the measurement circuit is configured to subtract the offset from the differential signal during the operating mode to generate a compensated differential signal.

2. The gas concentration sensor according to claim 1, wherein: During the operating mode, the compensated differential signal is a more accurate representation of the thermal conductivity of the target gas than the differential signal. The gas concentration sensor according to claim 1 , wherein the first voltage value is smaller than the second voltage value.

4. The gas concentration sensor of claim 1, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude less than the operational sensitivity to thermal conductivity.

5. The gas concentration sensor according to claim 1, wherein: During the calibration mode, the input voltage causes the first, second, third, and fourth piezoresistive lines to experience negligible temperature changes such that the differential signal is a measure of at least one offset effect.

6. The gas concentration sensor of claim 5, wherein the at least one offset effect comprises at least one of pressure, temperature, production diffusion, or lifetime drift.

7. The gas concentration sensor according to claim 5, wherein: During the operating mode, the input voltage causes the first and second piezoresistive lines to experience a first temperature increase based on a first heat release rate to the reference gas, and Wherein, during the operating mode, the input voltage causes the third piezoresistive line and the fourth piezoresistive line to experience a second temperature increase based on a second heat release rate to the target gas.

8. The gas concentration sensor according to claim 1, wherein the measurement circuit further comprises: a subtractor component configured to receive the differential signal, wherein the subtractor component is configured to output the differential signal during the calibration mode, and Wherein the subtractor component is configured to subtract the offset from the differential signal during the operating mode to generate the compensated differential signal.

9. The gas concentration sensor according to claim 8, wherein the measurement circuit further comprises: an analog-to-digital converter ADC coupled to the output of the subtractor component, wherein the ADC is configured to generate a digital signal based on the differential signal during the calibration mode; a scaler configured to amplify the digital signal by a scaling factor during the calibration mode to generate a scaled digital signal equal to the offset, wherein the scaling factor is equal to a ratio of the second voltage value to the first voltage value; as well as The digital-to-analog converter DAC is configured to receive the scaled digital signal and generate an analog offset signal based on the scaled digital signal.

10. The gas concentration sensor of claim 9, wherein the DAC is configured to provide the analog offset signal to the subtractor component during the operating mode, and Wherein the subtractor component is configured to subtract the analog offset signal from the differential signal during the operating mode to generate the compensated differential signal. 11 . The gas concentration sensor of claim 9 , wherein the ADC is configured to convert the compensated differential signal into a digital measurement signal during the operating mode, the digital measurement signal representing the thermal conductivity of the target gas.

12. A gas concentration sensor configured to measure the gas concentration of a target gas, the gas concentration sensor comprising: a reference chamber configured to contain a reference gas; a measurement chamber configured to contain the target gas different from the reference gas; as well as A measurement circuit is configurable in a calibration mode and an operation mode, the measurement circuit comprising: a resistance bridge circuit including a plurality of resistance elements, the plurality of resistance elements including at least one first resistance element arranged in the reference chamber and at least one second resistance element arranged in the measurement chamber, wherein the resistive bridge circuit is configured to receive an input voltage and to generate a measurement signal based on the input voltage, wherein, during the calibration mode, the input voltage has a first voltage value at which the resistive bridge circuit has a negligible sensitivity to thermal conductivity such that the measurement signal represents an offset, wherein during the operating mode, the input voltage has a second voltage value at which the resistive bridge circuit is sensitive to thermal conductivity with an operating sensitivity such that the measurement signal represents the thermal conductivity of the target gas, wherein the measurement circuit is configured to measure the offset based on the measurement signal during the calibration mode, and Wherein the measurement circuit is configured to subtract the offset from the measurement signal during the operating mode to generate a compensated measurement signal.

13. The gas concentration sensor according to claim 12, wherein: During the operating mode, the compensated measurement signal is a more accurate representation of the thermal conductivity of the target gas than the measurement signal. The gas concentration sensor according to claim 12 , wherein the first voltage value is smaller than the second voltage value.

15. The gas concentration sensor of claim 12, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude less than the operational sensitivity to thermal conductivity.

16. The gas concentration sensor according to claim 12, wherein: During the calibration mode, the input voltage causes the at least one first resistive element to undergo a first resistance change based on at least one offset effect, and Wherein, during the calibration mode, the input voltage causes the at least one second resistive element to experience a second resistance change based on the at least one offset effect.

17. The gas concentration sensor according to claim 16, wherein: During the operating mode, the input voltage causes the at least one first resistive element to undergo a third resistance change based on a first thermal interaction of the at least one first resistive element with the reference gas, and Wherein, during the operating mode, the input voltage causes the at least one second resistive element to experience a fourth resistance change based on a second thermal interaction of the at least one second resistive element with the target gas.

18. The gas concentration sensor according to claim 16, wherein: During the operating mode, the input voltage causes the at least one first resistive element to undergo a third resistance change based on the thermal conductivity of the reference gas, and Wherein, during the operating mode, the input voltage causes the at least one second resistive element to experience a fourth resistance change based on the thermal conductivity of the target gas.

19. A method for calibrating an offset of a gas concentration sensor, the method comprising: configuring a measurement circuit of the gas concentration sensor in a calibration mode; During the calibration mode, applying a first input voltage to a resistive bridge circuit of the gas concentration sensor to cause the resistive bridge circuit to generate a first measurement signal, wherein based on the first input voltage, the resistive bridge circuit has a negligible sensitivity to thermal conductivity such that the first measurement signal is representative of the offset; configuring a compensation component of the measurement circuit during the calibration mode using the offset derived from the first measurement signal; configuring the measurement circuit of the gas concentration sensor in an operating mode; During the operating mode, applying a second input voltage to the resistive bridge circuit of the gas concentration sensor to cause the resistive bridge circuit to generate a second measurement signal, wherein the second input voltage is greater than the first input voltage, and wherein, based on the second input voltage, the resistive bridge circuit is sensitive to thermal conductivity with an operational sensitivity such that the second measurement signal represents thermal conductivity of a measurement gas; and During the operating mode, the offset configured at the compensation component is subtracted from the second measurement signal to generate a compensated measurement signal.

20. The method of claim 19, wherein the negligible sensitivity to thermal conductivity is at least two orders of magnitude less than the operational sensitivity to thermal conductivity.

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