| 摘要 |
PURPOSE:To allow detection characteristics of high accuracy to be exhibited from the beginning by forming the atmosphere to which the sensor is exposed as an alternately changing lean-rich atmosphere and specifying an average air excess rate, the change width of the air excess rate and the lean-rich changing period. CONSTITUTION:The atmosphere to which the sensor is exposed is the alternately changing lean-rich atmosphere. The average air excess rate (-lambda), the change width (DELTAlambda) of the air excess rate and the lean-rich changing period (t) are so determined as to satisfy the conditions -lambda=0.95 to 1.05, DELTAlambda=0.05 to 0.5, t=0.5 to 300(s). The atmosphere to satisfy the conditions is approximate to the atmosphere by the exhaust gas in the initial driving period of an internal combustion engine. The gas adsorption state of oxygen, etc., on the surface of the detecting part of the oxygen sensor element can, therefore, be modified to the state similar to the state obtd. when the sensor is actually mounted. Since the alternately changing lean-rich atmosphere is formed, the rapid exchange of the atmosphere gas and the gas adsorbed on the surface of the detecting part is rapidly executed. The stabilization treatment by always the desired atmosphere is enabled in this way. |
