Title:
MEASURING METHOD OF INSIDE DIAMETER
Document Type and Number:
Japanese Patent JP3210491
Kind Code:
B2
Abstract:
PURPOSE: To provide a measuring method in which the inside diameter of a buried pipe such as a gas pipe or the like can be measured easily and surely.
CONSTITUTION: A transmitter 12 and a receiver 15 are inserted respectively into both sides of a pipe 2 to be measured. Radio waves at a prescribed frequency band are transmitted continuously from the transmitter 12, and they are received by the receiver 15. The receiver 15 investigates the strength of the received radio waves, and it finds a frequency at a point at which the strength is fluctuated largely. Then, the frequency at the point is substituted in the relational expression of the frequency to the inside diameter of the pipe: (inside diameter) = (light velocity)/(1.706 × frequency), and the smallest inside diamter of the pipe in a part to be inspected is computed.
Inventors:
Kiichi Suyama
Hajime Furusawa
Yasuharu Hosohara
Takashi Kobori
Hajime Furusawa
Yasuharu Hosohara
Takashi Kobori
Application Number:
JP16855193A
Publication Date:
September 17, 2001
Filing Date:
June 15, 1993
Export Citation:
Assignee:
Tokyo Gas Co., Ltd.
International Classes:
G01B15/00; G01N22/02; G01V3/12; (IPC1-7): G01B15/00; G01V3/12
Other References:
【文献】西独国特許出願公開2434856(DE,A1)
【文献】ソ連国特許発明508635(SU,A)
【文献】ソ連国特許発明508635(SU,A)
Attorney, Agent or Firm:
Hiroo Suzuki
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