ULTRASONIC FLOW-VELOCITY DISTRIBUTION METER/FLOWMETER, METHOD OF ULTRASONICALLY MEASURING FLOW VELOCITY DISTRIBUTION/FLOWRATE, PROGRAM FOR ULTRASONICALLY MEASURING FLOW VELOCITY DISTRIBUTION/FLOWRATE

摘要

An ultrasonic flowmeter 10 includes: emission trigger oscillating means 22 for outputting a trigger signal; ultrasonic oscillating means 23 for generating and outputting ultrasonic pulses by the trigger signal from said emission trigger oscillating means; ultrasonic pulse receiving means 24 for transmitting the ultrasonic pulses output from said ultrasonic oscillating means toward a measurement line within a fluid, and receiving an ultrasonic echo signal serving as reflected waves reflected off an ultrasonic reflector suspended within said fluid; signal processing means 25 for subjecting the ultrasonic echo signal received by said ultrasonic pulse receiving means to signal processing; and signal analyzing means 26 for analyzing the ultrasonic echo signal subjected to the signal processing by said signal processing means, calculating the position and speed of said ultrasonic reflector positioned along said measurement line, and measuring at least one of the flow-speed distribution and flow of said fluid from the calculated results, said signal processing 25 means comprising a band-pass filtering processing unit 31 for performing filtering processing for extracting the same frequency band as the ultrasonic pulses, of the received ultrasonic echo signals, an AD converter 32 for subjecting the ultrasonic echo signal received from said band-pass filtering processing unit to analog-to-digital conversion, and a wall filter processing unit 33 for subjecting the received ultrasonic echo signal to filtering processing using a wall filter.