To provide a flowrate measuring circuit of which the consumption current is not increased even when a measuring time interval is reduced in order to improve precision in measurement of change in a flowrate of a gas.
The flowrate measuring circuit 6 that drives an ultrasonic sensor 1 so as to measure a flowrate of a gas flowing in a measuring fluid path for each predetermined time interval in accordance with a propagation time of an ultrasonic wave, includes a data storage circuit 11 that stores flowrate values of a predetermined number of times of measurements. With the configuration, even when a flowrate measuring time interval is reduced as much as possible, a number of times of communications of data between the flowrate measuring circuit 6 and a control circuit 7 is not necessarily increased so that it is possible to improve precision in measurement of the flowrate by a small battery.
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KOBA YASUO
NAKAMURA HIROSUMI
IWAMOTO RYUJI
YOKOHATA MITSUO
OTANI TAKAHISA
SHIGEOKA TAKEHIKO
ASANO KAZUTAKA
UEKI KOICHI
MIYATA HAJIME
ITO YOICHI
| JP2006292377A | 2006-10-26 | |||
| JP2008275465A | 2008-11-13 |
Hiroki Naito
Daisuke Nagano