| 摘要 |
PURPOSE:To improve a safety against a gas accident without any trouble in practical use by a method wherein a flow rate pattern of gas is measured for a desired period of time and a judging condition corresponding to an actual condition for cut-off of gas is reset without any actual trouble at all. CONSTITUTION:When a starting signal applying means 10 is operated, a timer 9 starts to count for a desired period of time. During operation of a timer, a condition-of-use memory part 11 stores a total flow rate, a respective maximum flow rate and a continuous using time and the like. Final data is sent to a proper use condition changing part 12, where it is made to approximate a distribution function and a larger condition value is calculated in such a way as a desired probability value of occurrence, e.g., 0.0011 % is attained and is compared with an initial condition. Subsequently a smaller value is selected and a new proper using condition is reset to a more safe value. Until a timer counting is finished, the proper use condition part 8 compares it with a predetermined initial value to discriminate an abnormal condition. However, after a new condition is reset, it is compared with the reset value to discriminate the abnormal condition to operate a cut-off means 7. |
