US 12,392,742 B2
Thermal sensor device and method for determining a concentration of a target gas in a gas sample
Andreas Rüegg, Männedorf (CH); David Kiliani, Hombrechtikon (CH); Matthias Studer, Männedorf (CH); Nicolas Moeller, Stäfa (CH); Mark Hornung, Stäfa (CH); and Lukas Bürgi, Zurich (CH)
Assigned to Sensirion AG, Stäfa (CH)
Filed by Sensirion AG, Stäfa (CH)
Filed on Dec. 15, 2022, as Appl. No. 18/082,467.
Claims priority of application No. 21215403 (EP), filed on Dec. 17, 2021.
Prior Publication US 2023/0194450 A1, Jun. 22, 2023
Int. Cl. G01N 25/18 (2006.01)
CPC G01N 25/18 (2013.01) 18 Claims
OG exemplary drawing
 
1. A thermal sensor device for determining a concentration of a target gas in a gas sample that further comprises a disturbance gas, the thermal sensor device comprising:
a substrate having an opening or recess,
a first measurement bridge that spans the opening or recess, the first measurement bridge comprising a first temperature sensor for determining a first temperature signal, the first temperature signal being indicative of a temperature of the first measurement structure;
a second measurement bridge that spans the opening or recess, the second measurement bridge comprising a second temperature sensor for determining a second temperature signal, the second temperature signal being indicative of a temperature of the second measurement bridge;
at least one heater element operable to cause heat transfer to the first and second measurement bridges through the gas sample; and
processing circuitry configured to provide heating power to the at least one heater element and to derive an output signal based on a response of the first and second temperature signals to the heating power, the output signal being indicative of the concentration of the target gas in the gas sample,
wherein the first measurement bridge and the second measurement bridge differ with respect to dimensions and/or structure such that the first measurement bridge and the second measurement bridge have different thermal conductances, and
wherein the processing circuitry is configured to derive the output signal based on a weighted difference of the first and second temperature signals.