| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ultrasonic flow-velocity measuring apparatus in which phases of reflected ultrasonic waves are put in order so as to acquire coherent received waves and whose measuring accuracy can be ensured sufficiently by a method wherein an oval-shaped measuring part is formed inside a measuring pipe and transducers are arranged and installed in both focal positions of it. SOLUTION: An oval-shaped body shell 7 is installed in a measuring part 1a inside an ultrasonic flow-velocity measuring pipe 1, and transducers 2, 3 are arranged and installed in both focal positions of it. When ultrasonic waves are transmitted from a transmitting element at the transducer 2, a part of the ultrasonic wave reaches a receiving element at the transducer 3 as rectilinear propagation waves. However, the greater part of the ultrasonic waves are reflected only once by the inside wall of the oval-shaped body shell 7 so as to reach the receiving element at the transducer 3 in the focal position on the other side in the same time. Consequently, received waves which are output from an amplifier circuit 5 are changed into coherent waves in which phases are put in order and in which the reflected ultrasonic waves are overlapped. Then, a changeover circuit 6 is changed over, ultrasonic waves are transmitted from the transducer 3, and coherent waves are output from the circuit 5 in the same manner. Consequently, it is possible to obtain the measuring pipe 1 whose measuring accuracy can be ensured sufficiently. |
