摘要 |
PURPOSE:To allow a control center to decide the optimum exchange time of gas bombs by sending information from an automatic switching device for automatically switching a supplying gas bomb of a plurality of gas bombs to the control center through telecommunication lines. CONSTITUTION:A gas shortage sensor S6 is mounted to the upper portion of a negative pressure actuator 9 and includes a reed switch SW and a magnet Mg and transmits a gas shortage signal when the magnet Mg moves apart from the reed switch SW. The negative pressure actuator 9 is interposed between one gas bomb constituting a supplying gas bomb (a) and the other gas bomb constituting reserve gas bomb (b) and includes an intermediate-pressure regulating chamber 91 for control of switching of gas supply between the supplying gas bomb (a) and the reverse gas bomb (b). |