| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic gas meter capable of preventing wasted man hours and transportation cost from being caused by reducing erroneous shutoff while protecting safety and measurement performance, and to provide a control method for the ultrasonic gas meter. <P>SOLUTION: A μCOM 14 includes: an ultrasonic wave receiving error determination function which determines whether or not an ultrasonic signal is in a normal state where it is normally transmitted and received; a gain error determination function which determines whether or not the amplification degree for modifying the received ultrasonic signal is the normal state within a predetermined range; and a propagation time error determination function which determines whether or not the propagation time from transmission of the ultrasonic signal up to reception thereof is within a predetermined time range, and performs the closing operation of a gas shut-off valve 10 when the normal state is not determined. <P>COPYRIGHT: (C)2012,JPO&INPIT |
