| 摘要 |
PROBLEM TO BE SOLVED: To provide an application of a gas concn. sensor capable of measuring the concn. of gas with high accuracy and a control device of the gas concn. sensor. SOLUTION: In a step 100, it is judged whether there is a predetermined air flow rate and, in a step 110, processing for the correction of the zero point of a gas concn. sensor is executed. That is, in such a state that a purge valve is closed, the concn. of a purge gas due to the gas concn. sensor is measured and the sensor output S1 at this time is calculated. The sensor output S1 is compared with correct sensor output S0 to calculate the difference ΔS between both outputs. Therefore, at a time of the measurement of the concn. of gas thereafter, the value S3 calculated by subtracting the difference ΔS from the obtained sensor output S2 is employed as the correct sensor output. In the succeeding step 120, the supply amt. of the purge gas, therefore, the concn. of the purge gas is calculated. In the succeeding step 130, a purge valve is driven to supply a necessary supply amt. (A%) of the purge gas to a suction pipe. |
