| 摘要 |
PURPOSE:To switch over to reserve pressure containers so as to supply gas positively by measuring the weight of pressure containers upon removing plural pressure containers, and judging that replacement is performed normally when the specified conditions between the weight measured value and the average value are satisfied simultaneously. CONSTITUTION:Upon detecting the removal of plural pressure containers among pressure containers 1a, 1b, 2a, 2b filled with liquefied gas by a pressure detecting means 19, the lapse of the first preset time after the detection is detected, and the weight of the pressure containers is measured plural times every second preset fixed time so as to compute the average value of the weight measured value. A judgement is then made on whether or not satisfying the conditions that the present weight measured value is close to the average value, that the average value exceeds the weight immediately before the removal, and that the present value is below the value at the time of filling being completed and over the preset value in the range of exceeding the value of an empty container. When these three conditions are simultaneously satisfied, it is judged that the replacement of the pressure containers is performed normally. |
