Electromagnetic wave checking method for duct system

Abstract

An electromagnetic wave is propagated inside a pipe as an object of inspection from a transmission antenna of a transmitter, and a reception antenna of a receiver is moved along and outside the pipe so as to inspect it by receiving electromagnetic leakage. If a peak signal level is detected by the receiver, a defect is located where the pipe may be corroded or cracked or it has a joint. The transmission antenna can be moved along and outside the pipe while the reception antenna can be disposed at a suitable position of the pipe. The inspection described above can be conducted by moving both the transmission and reception antennas in synchronism with each other.

Description

[0001] The present invention is a divisional application of the No. 95191631.9 patent application filed on August 14, 1996, entitled "Electromagnetic wave inspection method for pipeline system components". technical field [0002] The present invention relates to the use of electromagnetic waves to inspect pipeline systems for city gas supply, etc., mainly buried in roads, etc., or installed in the walls of houses and under floors, etc., which are not exposed to the outside, and used to detect pipelines in its components Inspection methods for damaged parts such as corrosion holes or joints, etc. Background technique [0003] For example, in the pipeline system of the city gas supply system, check the gas leaked from the corrosion hole or the like that is not exposed to the outside of the buried gas pipeline, such as the smell inspection method, the method using a gas detector, And various methods such as the method of drilling in conjunction with these methods, inspections ...

AI Technical Summary

Problems solved by technology

And if just carry out construction work such as above-mentioned excavation or cut open wall according to such detection result, then this construction will cause waste, there is the problem that must carry out two, three constructions

In addition, even if gas leaks from the damaged part, if the leaked gas stays near the damaged part and does not diffuse into the air or indoors, the leak itself cannot be detected.

[0006] In this way, it is not always possible to accurately detect whether there is a leak and its location by detecting the composition of the gas itself that has leaked and diffused from the damaged site or the odor that has been added in advance to check the presence or absence of the leak.

[0007] On the other hand, as a conventional general inspection method for detecting damage to metal structures, there is an ultrasonic flaw detection method, but in this method, since the probe must be in contact with the flaw detection object, flaw detection over a long distance cannot be performed. and other reasons, it is difficult to apply to the inspection of the piping system that is not exposed

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