US 11,994,481 B2
Concentration measurement device
Susumu Kamiyama, Kyoto (JP); Hajime Kano, Kyoto (JP); Shinya Nakagawa, Kyoto (JP); Hideyuki Nakao, Kyoto (JP); Kenichi Handa, Kyoto (JP); and Takashi Kasai, Kyoto (JP)
Assigned to OMRON CORPORATION, Kyoto (JP)
Appl. No. 17/434,963
Filed by OMRON Corporation, Kyoto (JP)
PCT Filed Mar. 17, 2020, PCT No. PCT/JP2020/011702
§ 371(c)(1), (2) Date Aug. 30, 2021,
PCT Pub. No. WO2020/189677, PCT Pub. Date Sep. 24, 2020.
Claims priority of application No. 2019-051263 (JP), filed on Mar. 19, 2019.
Prior Publication US 2022/0136988 A1, May 5, 2022
Int. Cl. G01N 25/18 (2006.01); G01N 27/18 (2006.01)
CPC G01N 25/18 (2013.01) [G01N 27/18 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A concentration measurement device comprising:
a sensor configured to measure a concentration of a measurement target gas in a mixture of gases on the basis of thermal conductivity of the measurement target gas, the mixture of gases including two or more components; and
a heating unit configured to heat the mixture of gases so that the concentration of the measurement target gas can be uniquely determined with respect to the thermal conductivity,
wherein:
the sensor includes a pair of thermoelectromotive devices in which electromotive force according to temperature is generated and a heating unit that is placed between the pair of thermoelectromotive devices and that generates heat according to an applied voltage, and measures a flow rate of the mixture of gases according to the electromotive force generated in the pair of thermoelectromotive devices heated by the heating unit,
the concentration measurement device further includes a controller configured to control a voltage applied to the heating unit, and
the controller applies, to the heating unit, a second voltage higher than a first voltage that is applied when measuring a flow rate of the mixture of gases, and causes the sensor to measure a concentration of the measurement target gas.