Dynamic comparative diagnostics for catalytic structures and combustible gas sensors including catalytic structures

A method of operating a combustible gas sensor for detecting an analyte gas, the combustible gas sensor comprising a first element, the first element comprising 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 being configured to control a level of energy applied to the first element to control the temperature of the first element and to measure a response of the first element, the method comprising:

• operating the electronic circuitry 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 being heated to at least the first temperature, operating the electronic circuitry to initiate an interrogation of the first element during which the level of energy applied to the first element via the electronic circuitry is changed to induce a transition in a thermal state of the first element, and analyzing an associated dynamic response of the first element during the transition of the thermal state of the first element to determine if a threshold response associated with poisoning or inhibiting of the first catalyst has occurred, wherein the associated dynamic response is a change in a measured variable selected from a group consisting of current, voltage and resistance.

A combustible gas sensor for detecting an analyte gas, comprising:

• a first element, the first element comprising 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, a second element comprising a second electric heating element and a second support structure on the second electric heating element, the combustible gas sensor further comprising electronic circuitry in electrical connection with the first element and the second element, the electronic circuitry being configured to control a level of energy applied to the first electric heating element and the second electric heating element to control the temperature of the first element and the second element, the electronic circuitry further being configured, in a first mode, to provide energy to the first electric heating 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 further being configured in a second mode to initiate an interrogation of the first element, the interrogation comprising a change in the level of energy applied to the first electric heating element to induce a transition in a thermal state of the first element, the electronic circuitry further being configured to analyze an associated dynamic response during the transition in the thermal state of the first element and to determine from the associated dynamic response if a threshold response associated with poisoning or inhibiting of the first catalyst has occurred, wherein the associated dynamic response is a change in a measured variable selected from a group consisting of current, voltage and resistance.