| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a gas metering device having total flow rate shut-off function with higher accuracy than before. SOLUTION: The gas metering device 1 comprises gas metering means A and total flow rate shut-off function means B for monitoring the quantity of gas consumed determined in the gas metering means A and shutting-off gas supply when a gas flow rate exceeds a predetermined shut-off set value. The gas metering means A is mass flow type gas metering means A1 for measuring mass flow of the gas flow flowing in a gas flow passage, determining the gas flow rate based on the measured mass flow, and metering the quantity of gas consumed by integrating the determined gas flow rate value. The total flow rate shut-off function means B comprises forced learning means 15a11 for determining a maximum value of the gas flow rate measured by sampling by the mass flow type gas metering means A1 within a predetermined forced learning period and setting means 15a12 for setting the shut-off set value obtained from the maximum value determined by the forced learning means multiplied by a safety factor.</p> |
