Stress measurement by X-ray diffractometry
US4561062A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1983 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | Feb 18, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N23/207
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A portable X-ray diffractometer for measurement of residual stress in metallic specimens, especially large structures, such as bridges, pipelines etc. The instrument consists of a pair of position sensitive detectors arranged to be mounted in fixed positions relative to the specimen. An X-ray source that projects a collimated incident beam onto the area of the specimen under examination is located between the detectors so that each receives a diffraction line. The source is scanned stepwise in an arc about the specimen area, while the specimen and both the detectors remain fixed. The diffraction lines received in each detector are stored in a computer as histograms of intensity values. For each angular relationship between the incident beam and the chosen direction of strain measurement, a series of such intensity values corresponding to a given diffraction angle for successive diffraction lines is averaged and a resultant diffraction line obtained for each detector. To keep the mean strain directions constant and achieve a constant range of grain orientations for all diffraction angles, the instrument restricts the intensity values so averaged to those that fall within a virtual w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.