Gas concentration detector, fitted after the catalyst in the exhaust pipe of an internal combustion engine, has a sensor cell to measure a specific gas concentration and a monitor cell which measures oxygen

摘要

The gas concentration detector has a pump cell (140) in a leading chamber and a sensor cell (150), with a chamber (120) where the concentration of a specific gas is identified. A monitor cell (160) registers the oxygen concentration in its chamber (121), where the sensor and monitor cells have different oxygen reactivities. An electrical correction unit equalizes the output response sensitivity of the sensor and monitor cells to the changes in the oxygen concentration. The output signal from the monitor cell is smoothed by a band pass filter