| 摘要 |
PURPOSE:To improve safety, by a method wherein a flow rate pattern of gas is measured for a given period, and a deciding condition matching an actual state is reset. CONSTITUTION:With a starting signal applying means 10 actuated, a staring signal is sent to a timer 9, a timer receives a signal and starts integration of a period T1 in which a signal from a flow rate measuring means 3 exceeds a given value. Simultaneously with actuation of the timer, 5 a using state memory part 12 updates data in order to store a maximum value of each of a total flow rate, an individual maximum flow rate, and a continuous using time of gas. In which case, when an integrating value of the timer exceeds T1, final data is sent from the memory part to a proper using condition varying part 13. The varying part compares an initial condition with a final data, and by selecting whichever has a smaller value, of the initial condition and the final data, it is newly reset as a proper using condition. On and after the reset, a proper using condition deciding part 8 compares a new set condition with a signal from a using state detecting part 6, and when the comparing result is deviated from a condition, it is decided that abnormality has occurred and a shut-off means 4 is actuated. |
