Document Type and Number:
Japanese Patent JPH053528
Kind Code:
B2
Abstract:
PURPOSE:To measure flow rate at a high accuracy by a method wherein an ultrasonic pulse is transmitted to and received from a fluid of a pipeline and the received signal is compared with a comparison voltage to transmit an output pulse while the comparison voltage is decided optimally. CONSTITUTION:A pulse B is transmitted from an ultrasonic transmitter 5 and transmitted 3 to or received 4 from the flow of a fluid F of a pipeline 1 alternately varying the direction thereof by changing a selector switch 7. Then, the received signal H and a comparison voltage Vc from a D/A converter 10 are inputted into a comparator 9 and the part of the wavefrom surpassing the comparison voltage Vc is outputted as pulse output P. At this point, different reference voltages are outputted sequentially as comparison voltage Vc with a control circuit 14 to compute the size thereof with respect to the pulse output P thereby determining the optimum comparison voltage Vc. Then, the pulse output P is inputted into an arithmetic circuit 11 to determine flow rate from time difference between the pulse output P and the start pulse S of an ultrasonic pulse. Thus, the optimum comparison voltage can be determined with the control circuit though the amplitude of the ultrasonic pulse is almost constant thereby enabling highly accurate measurement of the flow rate.
Inventors:
AKYAMA CHUJI
SEKIGUCHI TOSHIO
SEKIGUCHI TOSHIO
Application Number:
JP13418884A
Publication Date:
January 18, 1993
Filing Date:
June 29, 1984
Export Citation:
Assignee:
YOKOGAWA ELECTRIC CORP
International Classes:
G01F1/66