| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve measurement accuracy during a high flow rate by changing a reference voltage to a stably measurable level in the case equal to or over a reference flow rate. <P>SOLUTION: A flow rate value calculated by a flow rate calculation means 11 is compared with the reference flow rate by a flow rate determination means 14. When the calculated flow rate is greater than the reference flow rate, a reference voltage value which is set by a reference voltage setting means 13 is changed, and thereby the zero-cross point of a reception waveform can be stably detected in an area in which the influence of the variation in the reception signal amplitude is small. Therefore, it is possible to provide a flow rate measuring device which can stably and precisely measure a flow rate even if the flow rate is high and has disturbances. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
