Method for providing calibration data for a gas sensor device, method of calibrating a gas sensor device, and processing device for a gas sensor device

A method of calibrating a gas sensor device,

• wherein the gas sensor device comprises a gas sensitive material electrically arranged between a first and second contact region, and a control electrode which is arranged neighboring to the gas sensitive material, wherein a resistance of the gas sensitive material has a dependency on an environmental target gas concentration and has a dependency on a control voltage applicable to the control electrode,
• the method comprising:
• applying the control voltage to the control electrode of the gas sensor device;
• determining measurement values of the resistance of the gas sensor device in response to the control voltage applied to the control electrode of the gas sensor device during a first clean air phase, a gas insertion phase, a natural recovery phase, and a second clean air phase, wherein the gas insertion phase and the natural recovery phase comprise non-overlapping time intervals;
• determining a first gas sensor behavior model based on the measurement values wherein the first gas sensor behavior model comprises a first fitting function comprising a first partial fitting function corresponding only to the gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to the natural recovery phase;
• providing calibration data for the gas sensor device, wherein the calibration data for the gas sensor device is derived from control voltage dependent resistance data over a control voltage range of the gas sensor device;
• determining a second gas sensor behavior model based on the calibration wherein the second gas sensor behavior model comprises a second fitting function comprising a first partial fitting function corresponding only to the gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to the natural recovery phase;
• comparing the measurement values of the resistance of the gas sensor device with the calibration data;
• adapting, using the first and second gas sensor behavior models, an output signal of the gas sensor device based on a measured difference between the measurement values of the resistance of the gas sensor device and the calibration data;
• determining, for different temperatures of at least one of the environmental target gas or the gas sensitive material, a control voltage dependent measurement value of the resistance of the gas sensitive material having within a tolerance range an insensitivity to the target gas concentration;
• and
• storing the determined control voltage dependent measurement value as a baseline calibration value in a memory device accessible to a processing device if a currently determined baseline calibration value differs from the baseline calibration value stored in the memory device, wherein the baseline calibration value is also independent of the temperature of at least one of the environmental target gas or the gas sensitive material exposed to the target gas.

A processing device for a gas sensor device for providing calibration data,

• wherein the gas sensor device comprises a gas sensitive material electrically arranged between a first and second contact region, and a control electrode which is arranged neighboring to the gas sensitive material, wherein a resistance of the gas sensitive material has a dependency on an environmental target gas concentration and has a dependency on a control voltage applicable to the control electrode,
• wherein the processing device is configured to:
• determine measurement values of the resistance of the gas sensitive material in response to an adjusted target gas concentration, during exposing the gas sensitive material of the gas sensor device to the adjusted target gas concentration;
• determine a first gas sensor behavior model based on the measurement values of the resistance of the gas sensitive material as a function of the adjusted target gas concentration, wherein the first gas sensor behavior model comprises a first fitting function comprising a first partial fitting function corresponding only to a gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to a natural recovery phase, wherein the gas insertion phase and the natural recovery phase comprise non-overlapping time intervals;
• translate the first gas sensor behavior model into a corresponding second gas sensor behavior model for the resistance of the gas sensitive material as a function of the control voltage applicable to the control electrode, wherein the second gas sensor behavior model comprises a second fitting function comprising a first partial fitting function corresponding only to the gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to the natural recovery phase;
• sweep the control voltage based on the second gas sensor behavior model over a control voltage range for providing control voltage dependent resistance data, wherein the provided control voltage dependent resistance data over a control voltage range of the gas sensor device or data derived therefrom form the calibration data for the gas sensor device;
• determine a control voltage dependent measurement value of the resistance of the gas sensitive material having a complete insensitivity to the target gas concentration for different temperatures of at least one of the environmental target gas or the gas sensitive material;
• and
• store the determined control voltage dependent measurement value as a baseline calibration value in a memory device accessible to the processing device, wherein the baseline calibration value is also independent of the temperature of at least one of the environmental target gas or the gas sensitive material exposed to the target gas.

A processing device for calibrating a gas sensor device,

• wherein the gas sensor device comprises a gas sensitive material electrically arranged between a first and second contact region, and a control electrode which is arranged neighboring to the gas sensitive material, wherein a resistance of the gas sensitive material has a dependency on an environmental target gas concentration and has a dependency on a control voltage applicable to the control electrode,
• wherein the processing device is configured to:
• apply the control voltage to the control electrode of the gas sensor device;
• determine measurement values of the resistance of the gas sensor device in response to the control voltage applied to the control electrode of the gas sensor device during a first clean air phase, a gas insertion phase, a natural recovery phase, and a second clean air phase, wherein the gas insertion phase and the natural recovery phase comprise non-overlapping time intervals;
• determining a first gas sensor behavior model based on the measurement values wherein the first gas sensor behavior model comprises a first fitting function comprising a first partial fitting function corresponding only to the gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to the natural recovery phase;
• provide calibration data for the gas sensor device, wherein the calibration data for the gas sensor device is derived from control voltage dependent resistance data over a control voltage range of the gas sensor device;
• determining a second gas sensor behavior model based on the calibration wherein the second gas sensor behavior model comprises a second fitting function comprising a first partial fitting function corresponding only to the gas insertion phase and a second fitting function comprising a second partial fitting function corresponding only to the natural recovery phase;
• compare the measurement values of the resistance of the gas sensor device with associated calibration data;
• adapt, using the first and second gas sensor behavior models, an output signal of the gas sensor device based on a measured difference between the measurement values of the resistance of the gas sensor device and the associated calibration data;
• and
• conduct an automatic baseline calibration of the gas sensor device based on the calibration data stored in a memory device accessible to the processing device, the processing device further configured to:
• determine a control voltage dependent measurement value of the resistance of the gas sensitive material having a complete insensitivity to the target gas concentration for different temperatures of at least one of the environmental target gas or the gas sensitive material;
• and
• store the determined control voltage dependent measurement value as a baseline calibration value in the memory device accessible to the processing device if a currently determined baseline calibration value differs from the baseline calibration value stored in the memory device, wherein the baseline calibration value is also independent of the temperature of at least one of the environmental target gas or the gas sensitive material exposed to the target gas.