Method and apparatus for detecting defective portion on outer surface of pipe
US4988210A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1989 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Mar 7, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N25/72
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for detecting a defective portion on the outer surface not exposed of a pipe, which comprises: heating or cooling a pipe, the outer surface of which is not exposed, from the side of the inner surface thereof so that a difference in temperature is produced between a portion of the inner surface of the pipe corresponding to an accumulation of foreign matters or a thinner portion as a defective portion on the outer surface not exposed of the pipe and a portion of the inner surface of the pipe corresponding to a normal portion of the outer surface of the pipe; then shooting the inner surface of the pipe by means of a thermal imaging system while the difference in temperature still remains on the inner surface of the pipe to obtain a thermal image of the difference in temperature; and detecting the accumulation of foreign matters or the thinner portion as the defective portion on the outer surface of the pipe by means of the thus obtained thermal image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.