To provide a bubble generator capable of measuring an accurate flow rate, irrespective of a pipe aperture and density of a reflecting body.
This bubble generator 10 is provided with a motor 11 installed in an upstream side of a fluid pipe 50 with respect to an ultrasonic transducer 2 to generate bubbles uniformly in a measured fluid, and using high pressure of nitrogen gas as a driving source, a rotary shaft member 12 rotated along a prescribed direction by driving force of the motor 11, extended in a downstream side of the motor 11, and provided with a gas injection port, and a porous material 15 fixed to cover the gas injection port in the rotary shaft member 12, and having a large number of pores passing freely the bubbles injected from the gas injection port.
TEZUKA KENICHI
TEZUKA HIDEAKI
Naruo Matoba