Parkhurst & Wendel, L.L.P.
Oxide sensor
 Disclosed is an oxide sensor in which a measuring electrode is arranged at a distance d to satisfy -3t.ltoreq.d.ltoreq.3t for a downstream end of an inner pumping electrode for a first chamber, i.e., the end located on a side of a second diffusion rate-determining section, provided that d represents a distance between the measuring electrode and the downstream end in a positive direction directed from the first chamber to a second chamber, and t represents a height of the first chamber. A partial pressure of oxygen in the first chamber is measured by using the measuring electrode. A main pumping cell is subjected to feedback control on the basis of a measured value so that the partial pressure of oxygen in the first chamber is controlled. After that, a measurement gas is introduced into the second chamber. Oxides contained in the measurement gas are decomposed by the aid of a detecting electrode or a catalyst. A partial pressure of oxygen produced by the decomposition is measured to determine the concentration of the oxides. Accordingly, it is possible to measure the oxides contained in the measurement gas with an extremely high degree of accuracy. Moreover, the obtainable oxide sensor is compact and inexpensive. 
NGK Insulators, Ltd.
Y Y G G
Y10T Y10T G01N G01N
additional additional inventional inventional
Nobuhide Kunihiko
Kato Nakagaki