Gas sensor

摘要

Provided is a gas sensor capable of accurately obtaining the concentrations of water vapor and carbon dioxide in a measurement gas. A main pumping cell adjusts an oxygen partial pressure of a first internal space such that water vapor and carbon dioxide in the measurement gas are all decomposed in the first internal space. A first measuring pumping cell adjusts an oxygen partial pressure of a second internal space such that hydrogen generated through the decomposition of water vapor is selectively burned. A second measuring pumping cell adjusts an oxygen partial pressure on the surface of a second measuring internal electrode such that carbon monoxide generated through the decomposition of carbon dioxide is all burned on the surface of the second measuring internal electrode. The concentration of water vapor is identified based on the magnitude of a current flowing between a first measuring internal electrode and an external electrode, and the concentration of carbon dioxide is identified based on the magnitude of a current flowing between the second measuring internal electrode and the external electrode.