Title:
DETECTING METHOD OF JOINT OF PIPELINE BY ACOUSTIC WAVE
Document Type and Number:
Japanese Patent JP3113128
Kind Code:
B2
Abstract:
PURPOSE: To enable detection of the existence and position of a joint by detecting a reflected wave appearing between a pulse-shaped acoustic wave transmitted from the other end side of a pipeline and a reflected wave from an open or closed end.
CONSTITUTION: A longitudinal straight pipe part 7, for instance, of a supply pipe 1 is disconnected from a meter cock and a detecting part (an acoustic wave transmitting part 9, a receiving part 10) 11 is fitted to the upper end of the straight pipe part 7. The transmitting part 9 is constructed of a speaker converting a signal from a pulse generating means 12 into an audio signal, and an output signal of a microphone constructing the receiving part 10 is inputted to a signal processing means (CPU, etc.) 14 through a preprocessing means (an amplifier, an A/D converter, etc.) 13. A signal obtained by the processing means 14 is outputted to an output means 15. Two detection outputs of a transmitted pulse-shaped acoustic wave and a reflected wave from an open end of the pipeline 1 obtain high levels and a detection output having a low level appears between the two. This is a reflected wave from a joint. This wave can be discriminated distinctly and the presence of the joint can be detected. The position of the joint can be calculated from an acoustic wave pass time and a sound velocity.
Inventors:
Hideo Tai
Hiroshi Suzuki
Sofumi Sato
Hiroshi Suzuki
Sofumi Sato
Application Number:
JP20309293A
Publication Date:
November 27, 2000
Filing Date:
August 17, 1993
Export Citation:
Assignee:
Tokyo Gas Co., Ltd.
International Classes:
G01N29/09; G01V1/00; (IPC1-7): G01V1/00; G01N29/16
Domestic Patent References:
| JP3282290A | ||||
| JP1237484A | ||||
| JP6375554A |
Attorney, Agent or Firm:
Koji Misaki