| 摘要 |
The present invention provides an exhaust emission purifying apparatus having a liquid level measuring device in which, when a liquid level (measured liquid level) measured by a liquid level indicator of a sensor is equal to or than a measurable lower limit, the measured liquid level is output. On the other hand, when the measured liquid level is less than the measurable lower limit, the liquid level estimated based on a consumption of a liquid reducing agent or its precursor in a reducing agent tank and a tank cross-sectional area is output. The liquid level of the liquid reducing agent or its precursor is estimated in a range in which the liquid level may not be accurately measured due to the presence of a concentration meter, whereby the liquid level can be measured over a wide range. |
