| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas shut-off device capable of preventing the erroneous determination of inner tube leakage.SOLUTION: A gas shut-off device comprises: first section calculation means 7 that calculates an average flow rate at a first section by accumulating a flow rate for a prescribed time; second section calculation means 8 that accumulates the flow rate from the first section calculation means 7, calculates an average flow rate at a second section made up of a plurality of first sections, and selects the maximum first section average flow rate and minimum first section average flow rate during the time; and flow rate presence/absence determination means 9 that determines whether or not there is a gas flow rate on the basis of the flow rate from the second section calculation means 8. The flow rate presence/absence determination means 9 determines there is no flow rate if the second section average flow rate Qt is within a determination permissible range, and if the second section average flow rate is within an average determination flow rate in the case where difference between the maximum value and minimum value of the first section calculation value from the first section calculation means 7 is within a determination range, and determines there is a flow rate if the second section average flow rate is larger than the average determination flow rate.SELECTED DRAWING: Figure 1 |
