Method of operating gas sensors and corresponding device, sensor and program product

A device, comprising:

• a sensor including a sensing element configured to produce a sensing signal indicative of a target gas, and including a first power node to receive electrical power;
• and
• a circuit including:
• an input node coupled to the sensor to receive the sensing signal;
• a second power node coupled to the first power node of the sensor;
• and
• processing circuitry coupled to the input node and the second power node, the processing circuitry configured to:
• apply current to the second power node to generate heat that is applied to the sensing element;
• detect a presence of the target gas based on the sensing signal;
• measure, in response to detecting the presence of the target gas, first electrical resistance of the sensing element in a first time interval in which the heat applied to the sensing element is modulated;
• measure, in response to detecting the presence of the target gas, second electrical resistance of the sensing element in a second time interval in which the heat applied to the sensing element is constant without modulation;
• obtain a trajectory of the target gas in three dimensions having a first axis corresponding the first electrical resistance, a second axis corresponding to the current, and a third axis corresponding to the second electrical resistance;
• recognize the target gas by comparing said trajectory in the three dimensions to a set of reference three-dimensional objects that are each represented according to the three dimensions and that are associated with a plurality of different target gases, respectively.

A computer program product, loadable in a memory of processing circuitry, the computer program product including software code portions which, when the computer program product is executed on the processing circuitry, cause the processing circuitry to carry out the operations of:

• applying heat by a heater to a metal oxide sensing element of a gas sensor by applying a heating current to the heater;
• detecting, by the gas sensor, a presence of a target gas;
• measuring, in response to detecting the presence of the target gas, first electrical resistance of said metal oxide sensing element of the gas sensor in a first time interval in which the heat applied to the metal oxide sensing element is modulated;
• measuring, in response to detecting the presence of the target gas, second electrical resistance of said metal oxide sensing element of the gas sensor in a second time interval in which the heat applied to the metal oxide sensing element is constant without modulation;
• obtaining a trajectory of the target gas in three dimensions having a first axis corresponding to the first electrical resistance, a second axis corresponding to the heating current, and a third axis corresponding to the second electrical resistance;
• and
• recognizing the target gas by comparing said trajectory in the three dimensions to a set of reference three-dimensional objects that are each represented according to the three dimensions and that are associated with a plurality of different target gases, respectively.