Abstract: A water level measuring apparatus and a water level measuring method, in which a water level L0 of a liquid is read from a water level indicator secured to a liquid tank, and a filter value FLT is calculated by applying a filter with a time constant greater than one second to the water level L0, and the filter value FLT is output as a final water level L. Accordingly, even if the surface sloshes and the water level L0 fluctuates up and down, the water level L0 is smoothed by the filter. Hence there is little influence of the liquid sloshing, and the water level measurement accuracy can be improved.

Abstract: A sensor control apparatus (1) connected to a gas sensor (2) includes a microcomputer (10) containing a ROM (12) (first storage section), and an EEPROM (30) (second storage section) independently of the ROM (12). The ROM (12) stores an anomaly diagnosis program containing at least one type of anomaly determination process. The EEPROM (30) stores one or more flags set so as to represent whether the corresponding anomaly determination process is valid or invalid. The states of the one or more flags can be readily changed from an externally connected PC (3). A CPU (11) executes a series of processing steps of the anomaly determination processes, and then obtains a determination result thereof when the CPU (11) determines that the anomaly determination process is valid, with reference to the one or more flags.

Abstract: In an exhaust emission purifying apparatus for reductively purifying NOx in the exhaust emission by using a liquid reducing agent or its precursor, to be referred to as “liquid reducing agent” herein, a dosing flow rate of the liquid reducing agent according to engine operating conditions is computed, and the dosing of the liquid reducing agent is controlled based on the computed dosing flow rate, and also, it is judged whether or not a supply system of the liquid reducing agent is failed, based on a ratio between an integrated amount obtained by sequentially integrating the dosing flow rate and a consumed amount of the liquid reducing agent.

Abstract: An oxygen sensor control apparatus (10) obtains a correction coefficient for calibrating the relation between oxygen concentration and an output value of an oxygen sensor (20), when a fuel cut operation of an internal combustion engine (100) is performed. The apparatus includes average output value calculation means; inter-fuel-cut average output value calculation means; and correction coefficient calculation means.

Abstract: In an exhaust emission purifying apparatus for reductively purifying NOx in the exhaust emission by using a liquid reducing agent or its precursor, to be referred to as “liquid reducing agent” herein, a dosing flow rate of the liquid reducing agent according to engine operating conditions is computed, and the dosing of the liquid reducing agent is controlled based on the computed dosing flow rate, and also, it is judged whether or not a supply system of the liquid reducing agent is failed, based on a ratio between an integrated amount obtained by sequentially integrating the dosing flow rate and a consumed amount of the liquid reducing agent.

Abstract: A water level measuring apparatus and a water level measuring method, in which a water level L0 of a liquid is read from a water level indicator secured to a liquid tank, and a filter value FLT is calculated by applying a filter with a time constant greater than one second to the water level L0, and the filter value FLT is output as a final water level L. Accordingly, even if the surface sloshes and the water level L0 fluctuates up and down, the water level L0 is smoothed by the filter. Hence there is little influence of the liquid sloshing, and the water level measurement accuracy can be improved.