| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the change with the lapse of time of a flow rate sensor by providing a check passage for making a gas of a flow rate integrated value smaller than the flow integrated value to flow in a measuring passage flow, in such a manner as to bypass a main passage. SOLUTION: A check program prepared separately from a sensor check program has a constitution, for example, for stopping the heating of the heater element of a measuring flow velocity sensor 32 to check whether the output value of the measuring flow velocity sensor 32 outputted at that time shows substantially zero value or not, thereby, whether the measuring flow velocity sensor 32 is broken or not, is judged. A combustion control program closes a main passage cutoff valve 34 which was opened till then, when the failure of the measuring flow velocity sensor 32 is detected, and also opens first and second branched passage cutoff valves 35, 36 which where closed till then, thereby, the gas which has flowed through a gas main passage 30 till then is controlled so as to flow through a gas branched passage 31, and the output value of a comparing flow velocity sensor 33 is then selectively inputted, thereby, the flow rate of the gas flowing through the gas main passage 30 is detected.</p> |
