| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To surely detect whether a cut-off valve is functioned correctly or not, by a simple technique, without impairing convenience for a user, in a gas meter provided with the cut-off valve and a safety means. <P>SOLUTION: An abnormality deciding and control circuit 40 monitors gas pressure by a pressure sensor (pressure measuring means), and conducts control to bring the cut-off valve 94 into a closed condition, when the presence of a prescribed condition is determined in the gas meter by a safety unit 90, for example, when an earthquake is generated, or when a battery is run down. The occurrence of abnormality in a valve opening and closing operation for the cut-off valve is decided when pressure is reduced in the gas pressure thereafter, and when pressure increase having a prescribed level or more of fluctuation amount is caused further thereafter. <P>COPYRIGHT: (C)2004,JPO</p> |
