| 摘要 |
PROBLEM TO BE SOLVED: To reduce variation among flowmeters to keep the variation among the flowmeters substantially constant, ranging over an area from a laminar flow of a small flow rate up to a turbulent flow of a large flow rate. SOLUTION: A flow passage 1 has a rectangular cross section having a short side W and a long side H' between parallel opposed faces 3E, 3F. An upstream end face and a downstream end face of a flow tube 3 are formed into a machined face shape as shown in Fig. (c), (d). A flow velocity becomes large in a position separated from the center end X-X along a long side H' direction of the flow passage 1, and a flow velocity distribution becomes flat as a curve F. An ultrasonic wave is propagated between ultrasonic oscillators along a propagation route 6. The flow velocity/flow rate is found based on a propagation time. COPYRIGHT: (C)2005,JPO&NCIPI
|
