| 摘要 |
<P>PROBLEM TO BE SOLVED: To execute appropriate gain calibration for a NOx sensor. <P>SOLUTION: A NOx sensor output calibrator includes: a urea addition valve 40 through which urea is added to an exhaust passage 15 of an internal combustion engine; the NOx sensor 50 disposed at least downstream from the urea addition valve 40 and capable of detecting ammonia concentration besides NOx concentration; a fuel cut means executing fuel cut to the internal combustion engine; and a calibration means 100 calibrating the gain of the NOx sensor 50 based on ammonia derived from the urea added from the urea addition valve 40 while the fuel cut is executed. The ammonia derived from the urea added during the execution of fuel cut is used as a reference gas to execute gain calibration for the NOx sensor. <P>COPYRIGHT: (C)2010,JPO&INPIT |
