US 12,140,561 B2
Gas sensor
Tadakatsu Koyabu, Kariya (JP); Yu Murata, Kariya (JP); Yusuke Kawamoto, Kariya (JP); and Tomonori Ezaki, Obu (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Jul. 30, 2021, as Appl. No. 17/389,527.
Application 17/389,527 is a continuation of application No. PCT/JP2019/050736, filed on Dec. 25, 2019.
Claims priority of application No. 2019-016220 (JP), filed on Jan. 31, 2019.
Prior Publication US 2021/0356424 A1, Nov. 18, 2021
Int. Cl. G01N 27/419 (2006.01); G01N 27/409 (2006.01); G01N 27/41 (2006.01)
CPC G01N 27/419 (2013.01) [G01N 27/409 (2013.01); G01N 27/41 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A gas sensor comprising:
a measurement chamber into which exhaust gas is introduced;
a reference gas chamber into which a reference gas is introduced;
a first cell that includes a first electrode that is provided in the measurement chamber and a second electrode that is provided in the reference gas chamber, and removes oxygen that is contained in the exhaust gas that is introduced into the measurement chamber by a voltage being applied between the first electrode and the second electrode;
a second cell that includes a third electrode that is provided in the measurement chamber and a fourth electrode that is provided in the reference gas chamber, in which a voltage is applied between the third electrode and the fourth electrode, and through which a second current flows which depends on a concentration of a specific gas component that is contained in the exhaust gas from which oxygen has been removed by the first cell; and
a control circuit, wherein the control circuit is configured to:
detect a value of a first current that flows between the first electrode and the second electrode;
detect a value of the second current;
calculate the concentration of the specific gas component based on the detected value of the second current; and
estimate a change amount of oxygen concentration in the reference gas chamber per unit time that is a rate of change with time of the detected value of the first current, based on the detected value of the first current, and correct the detected value of the second current, based on the estimated change amount of the oxygen concentration in the reference gas chamber per unit time.