To solve a problem in finding the propagation time of an ultrasonic wave in which a time lag arises between measurements, such as measurement - switching - measurement, since an operation takes place for switching between a transmission-side oscillator and a reception-side oscillator.
A flow rate operation means 38 is capable of calculating a flow velocity by separating time periods of opposite propagation from each other based on timing values obtained by a first clocking means 36 for measuring a time period taken by an ultrasonic signal directly propagating between vibrators 32 and 33, and by a second clocking means 37 for measuring a propagation time period taken by an ultrasonic signal reflecting at least twice between the vibrators 32 and 33 so as not to cause a substantial time lag.
COPYRIGHT: (C)2008,JPO&INPIT
Koichi Takemura
Yuji Nakabayashi
Villa Daisuke
| JP2005172556A | ||||
| JP11051724A | ||||
| JP63233334A | ||||
| JP58167918A |
Daisuke Nagano
Kentaro Fujii