| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve measurement accuracy by synchronizing a drive frequency of a piezoelectric element with a resonance frequency. <P>SOLUTION: In the period between the start and end of a flow rate measurement, a resonance frequency of piezoelectric elements 2, 3 is measured based on a signal obtained from a current measurement circuit 16 or (and) a current measurement circuit 17, and a drive frequency for driving piezoelectric elements 2, 3 is synchronized with the resonance frequency in the next flow rate measurement. <P>COPYRIGHT: (C)2012,JPO&INPIT |
