To determine the concentration of CO in the exhaust gas from a burner where the combustion load fluctuates significantly by modifying an electrode material, composed of the mixture of a platinum group metal and an oxygen ion conductive solid electrolyte, with a specified transition metal oxide.
The electrode material of a solid electrolyte CO sensor composed of the mixture of a platinum group metal and an oxygen ion conductive solid electrolyte is modified with a specified transition metal oxide. Consequently, the adverse effect of H2 in exhaust gas 6 on the detection sensitivity of CO is suppressed. More specifically, CO and H2 in exhaust gas 6 causes electrochemical reaction on the oxygen ion at the three-phase interface of exhaust gas 6, a modification electrode 1, and an oxygen ion conductive solid electrolyte substrate 3 and the electrochemical reaction of H2 is suppressed. On the other hand, a modification electrode 2 covered with a combustible gas oxidizing catalyst 4 oxidizes CO and H2 which can not thereby reach the modification electrode 2. Consequently, an electromotive force appears between the electrodes 1, 2 and the value thereof is indicated by an indicating instrument 7.
TANDA AKIFUMI
MOCHIZUKI KAZU
TAKASHIMA HIROMASA
YASUGATA KAZUTOSHI
YAZAKI CORP
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