Abstract: A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

Abstract: A gas sensor device includes a sensing element including a heating element and electronic circuitry in connection with the heating element. The sensing element forms resistive element in a circuit of the electronic circuitry. The electronic circuity operates the sensing element in a trigger mode via a pulsed energy input to the heating element at a first duty cycle and in a primary mode via a pulsed energy input to the heating element at a second duty cycle, which is greater than the first duty cycle. The electronic circuitry is further configured to measure a response of the sensing element over time during each pulse of a plurality of pulses of the pulsed energy input. The primary mode is entered upon measurement of a value of a response at or above a threshold value in the trigger mode of operation.

Abstract: A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to provide energy to the first element to heat the first element to at least a first temperature at which the first catalyst catalyzes combustion of the analyte gas and to determine if the analyte gas is present based on a response of the first element to being heated to at least the first temperature. The electronic circuitry is further configured to apply an interrogation pulse to the first element in which energy to the first element is increased or decreased to induce an associated response from the first element.

Abstract: A method of operating a sensing element including a heating element in operative connection with electronic circuitry, wherein the sensing element forms a resistive element in a circuit of the electronic circuitry, includes, in at least a first phase, activating the electronic circuitry to heat the sensing element to a temperature at which the sensing element is responsive to an analyte gas via energy input to the heating element in a pulsed manner. A constant resistance setpoint is set for the sensing element and energy through the circuit is variably controlled via the pulsed energy input toward achieving the constant resistance setpoint. The method further includes measuring a response of the sensing element over time to the pulsed energy input.

Abstract: A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

Abstract: A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

Abstract: A sensor system for detecting mass deposition from a gaseous environment includes a first sensor element including a first electrically conductive heating component and a first interface structure on the first electrically conductive heating component. The sensor system further includes electronic circuitry in connection with the first electrically conductive heating component. The electronic circuitry is configured to provide energy to the first electrically conductive heating component to heat the first sensor element and to measure a thermodynamic response of the first sensor element, which varies with mass deposition of one or more compositions on the first interface structure.

Abstract: A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to provide energy to the first element to heat the first element to at least a first temperature at which the first catalyst catalyzes combustion of the analyte gas and to determine if the analyte gas is present based on a response of the first element to being heated to at least the first temperature. The electronic circuitry is further configured to apply an interrogation pulse to the first element in which energy to the first element is increased or decreased to induce an associated response from the first element.

Abstract: A method of operating a sensing element including a heating element in operative connection with electronic circuitry, wherein the sensing element forms a resistive element in a circuit of the electronic circuitry, includes, in at least a first phase, activating the electronic circuitry to heat the sensing element to a temperature at which the sensing element is responsive to an analyte gas via energy input to the heating element in a pulsed manner. A constant resistance setpoint is set for the sensing element and energy through the circuit is variably controlled via the pulsed energy input toward achieving the constant resistance setpoint. The method further includes measuring a response of the sensing element over time to the pulsed energy input.

Abstract: A system includes a primary combustible gas sensor and a trigger combustible gas sensor including a first trigger element of low-thermal-mass which includes a first trigger heating element in operative connection with electronic circuitry. The trigger combustible gas sensor also includes a second trigger element of low thermal mass including a second trigger heating element. The second trigger element is also in operative connection with the electronic circuitry. The electronic circuitry further has a first trigger mode of operating in which the first trigger element is heated to a temperature at or above a temperature at which the first trigger element causes combustion of the at least one combustible gas analyte and wherein the second trigger element is operated as a trigger compensating element. The electronic circuitry is configured to operate the trigger combustible gas sensor to detect a value of a response at or above a threshold value.

Abstract: A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to provide energy to the first element to heat the first element to at least a first temperature at which the first catalyst catalyzes combustion of the analyte gas and to determine if the analyte gas is present based on a response of the first element to being heated to at least the first temperature. The electronic circuitry is further configured to apply an interrogation pulse to the first element in which energy to the first element is increased or decreased to induce an associated response from the first element.

Abstract: A system includes a primary combustible gas sensor and a trigger combustible gas sensor including a first trigger element of low-thermal-mass which includes a first trigger heating element in operative connection with electronic circuitry. The trigger combustible gas sensor also includes a second trigger element of low thermal mass including a second trigger heating element. The second trigger element is also in operative connection with the electronic circuitry. The electronic circuitry further has a first trigger mode of operating in which the first trigger element is heated to a temperature at or above a temperature at which the first trigger element causes combustion of the at least one combustible gas analyte and wherein the second trigger element is operated as a trigger compensating element. The electronic circuitry is configured to operate the trigger combustible gas sensor to detect a value of a response at or above a threshold value.

Abstract: A system for detecting an analyte gas in an environment includes a first gas sensor, a first contaminant sensor separate and spaced from the first gas sensor, and electronic circuitry in electrical connection with the first gas sensor to determine if the analyte gas is present based on a response of the first gas sensor. The electronic circuitry is further in electrical connection with the first contaminant sensor to measure a response of the first contaminant sensor over time. The measured response of the first contaminant sensor varies with an amount of one or more contaminants to which the system has been exposed in the environment over time.

Abstract: A sensor system for detecting mass deposition from a gaseous environment includes a first sensor element including a first electrically conductive heating component and a first interface structure on the first electrically conductive heating component. The sensor system further includes electronic circuitry in connection with the first electrically conductive heating component. The electronic circuitry is configured to provide energy to the first electrically conductive heating component to heat the first sensor element and to measure a thermodynamic response of the first sensor element, which varies with mass deposition of one or more compositions on the first interface structure.

Abstract: A combustible gas sensor including a first sensing element having a catalyst and a heating element and electronic circuitry in operative connection with the heating element of the first sensing element to change a temperature thereof between a temperature above a temperature to catalyze oxidative combustion and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of a plurality of gas analytes of interest. The electronic circuitry being configured to determine a species of at least one of the plurality of gas analytes of interest from a first, dynamic output of the combustible gas sensor while the temperature of the first sensing element is changing. The electronic circuitry further being configured to determine a concentration of the species from a second output of the combustible gas sensor.

Abstract: A combustible gas sensor for detecting an analyte gas includes a first element including a first electric heating element, a first support structure on the first electric heating element and a first catalyst supported on the first support structure and electronic circuitry in electrical connection with the first element. The electronic circuitry is configured to operate in a first mode in which the first element is operated at a first temperature at which the first catalyst catalyzes combustion of the analyte gas, and in a second mode wherein the first element is operated at a second temperature which is below the temperature at which the first catalyst catalyzed combustion of the analyte gas but at which Joule heating of the first element occurs. The electronic circuitry is further configured to measure a variable in the second mode related to a mass of the first element.

Abstract: A system includes a primary combustible gas sensor and a trigger combustible gas sensor including a first trigger element of low-thermal-mass which includes a first trigger heating element in operative connection with electronic circuitry. The trigger combustible gas sensor also includes a second trigger element of low thermal mass including a second trigger heating element. The second trigger element is also in operative connection with the electronic circuitry. The electronic circuitry further has a first trigger mode of operating in which the first trigger element is heated to a temperature at or above a temperature at which the first trigger element causes combustion of the at least one combustible gas analyte and wherein the second trigger element is operated as a trigger compensating element. The electronic circuitry is configured to operate the trigger combustible gas sensor to detect a value of a response at or above a threshold value.

Abstract: A combustible gas sensor including a first sensing element having a catalyst and a heating element and electronic circuitry in operative connection with the heating element of the first sensing element to change a temperature thereof between a temperature above a temperature to catalyze oxidative combustion and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of a plurality of gas analytes of interest. The electronic circuitry being configured to determine a species of at least one of the plurality of gas analytes of interest from a first, dynamic output of the combustible gas sensor while the temperature of the first sensing element is changing. The electronic circuitry further being configured to determine a concentration of the species from a second output of the combustible gas sensor.

Abstract: A combustible gas sensor includes a first sensing element, which includes a catalyst and a heating element in operative connection with the catalyst to heat the catalyst above a temperature to combust gas analytes of interest, and electronic circuitry in operative connection with the heating element of the first sensing element to periodically cycle the first sensing element between a temperature above the temperature to combust the analytes of interest and a temperature at which the catalyst is substantially inactive to catalyze oxidative combustion of the analytes of interest. The electronic circuitry is adapted to determine a species of at least one of the gas analytes of interest from a first output of the combustible gas sensor during an ON time within a cycle duration. The electronic circuitry is further adapted to determine a concentration of the species of gas from a second output of the combustible gas sensor.

Abstract: A filter includes a filter media material through which a gas is transportable, a first metal salt immobilized upon the filter media material and a second metal salt immobilized upon the filter media material, wherein the first metal salt and the second metal salt are immobilized upon the filter media material from an aqueous solution comprising the first metal salt and the second metal salt.