US 11,698,355 B2
Method of operating a gas sensing device, and corresponding gas sensing device
Fabio Passaniti, Syracuse (IT); and Enrico Rosario Alessi, Catania (IT)
Assigned to STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed by STMICROELECTRONICS S.r.l., Agrate Brianza (IT)
Filed on Jun. 30, 2020, as Appl. No. 16/917,285.
Claims priority of application No. 102019000010647 (IT), filed on Jul. 2, 2019.
Prior Publication US 2021/0003524 A1, Jan. 7, 2021
Int. Cl. G01N 27/04 (2006.01); G01N 33/00 (2006.01)
CPC G01N 27/045 (2013.01) [G01N 33/0031 (2013.01); G01N 33/0063 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method of operating a gas sensing device, the method comprising:
receiving a first signal from a gas sensor circuit having a resistive gas sensing element, the first signal being indicative of a resistance value of the resistive gas sensing element;
processing the first signal to compute a value of a gas concentration;
comparing the value of gas concentration to a threshold value; and
setting the gas sensing device to an alert signal issue state based on an outcome of the comparing, wherein the setting the gas sensing device to the alert signal issue state includes a diagnosis procedure, the diagnosis procedure including:
computing a set of parameters indicative of a state of the gas sensor circuit;
classifying the gas sensor circuit, based on values of the parameters in the set of parameters computed, in one of a first class, a second class and a third class indicative of the gas sensor circuit being faulty, degraded, or correctly operating, respectively; and
in response to the gas sensor circuit being classified in the first class, disabling the setting the gas sensing device to the alert signal issue state;
in response to the gas sensor circuit being classified in the second class, triggering a sensitivity correction procedure of the gas sensor circuit;
in response to the gas sensor circuit being classified in the third class, enabling setting the gas sensing device to the alert signal issue state; and
counting a number of consecutive executions of the sensitivity correction procedure.