| 摘要 |
PROBLEM TO BE SOLVED: To achieve a higher measuring accuracy of NOx by lessening an offset valve to such an extent as not to disturb measurement without causing a reduction of the NOx. SOLUTION: In this sensor, NOx contained in a gas to be measured introduced to a second chamber is decomposed by catalytic action and/or electrolysis and oxygen generated by the decomposition undergoes a pumping processing to measure the NOx based on a pump current flowing through a pump cell for measurement. In this case, out of patterns of a heater 94, those 94a are dense in pitch at a part corresponding to the tip side of a sensor element 100, those 94b coarse in pitch at the central part thereof and moreover, those 94c at a part corresponding to the rear end part of the sensor element 100 are removed. An electrical resistivity in the electronic conductivity of the pump cell for measurement is >=1 MΩ in terms of resistance value. |
