Title:
超音波流量計
Document Type and Number:
Japanese Patent JP4485641
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize a small-sized flowmeter for a liquid which achieves a higher accuracy thereof and a reduction in current consumption by upgrading a measuring solving power of the arrival time of an ultrasonic wave without elevating the frequency of a reference clock. SOLUTION: One of transmitter/receivers is driven to transmit an ultrasonic pulse. The arrival time is measured up to a reception point of a received wave from a transmission drive as follows: The number n' of reference clocks is measured immediately after the reception point from the transmission drive. Time T1 to the reference clock n' immediately after the reception point starting from the point is multiplied by m to make a time pulse with a pulse length mT1. The length of mT1 is measured by the reference clocks. When the results of the measurement are represented by k, the arrival time is determined by the resolving power equivalent to 1/m of one cycle T of the reference clock by T (n'-k/m).
Inventors:
Takagi Katsumasa
Kazuo Yamada
Noriyuki Nabeshima
Kazuo Yamada
Noriyuki Nabeshima
Application Number:
JP2000071909A
Publication Date:
June 23, 2010
Filing Date:
March 15, 2000
Export Citation:
Assignee:
Aichi Clock Electric Co., Ltd.
International Classes:
G01F1/66
Domestic Patent References:
| JP60225027A | ||||
| JP55134385A | ||||
| JP9243422A |
Attorney, Agent or Firm:
Hasegawa Yoshimichi