| 摘要 |
<p>This is for controlling the quality of reductant that is used in an exhaust gas, or selective catalytic reduction (SCR) system. There is a control assembly 10 that measures a plurality of values over a predetermined time that indicate the content of NOx or nitrous oxides downstream from the catalytic device 12. The quality of the reducing agent that is supplied to the catalytic device is assessed based on these values. First it is determined whether or not the reducing agent has been filled into a storage tank 16. Then the magnitude and frequency of the measuring values are analysed to assess the quality or concentration of the reducing agent. The amount of noise from the NOx sensor in the tailpipe is also used to assess the quality of the reductant. If it is noisy then it indicates that the reductant is of poor quality.</p> |
