Self-calibration system for ultrasonic inspection apparatus
US4567747A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 16, 1984 |
| Grant date | Feb 4, 1986 |
| Priority date | — |
| Expiry date | Jan 16, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N29/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tubular workpiece (10) undergoes axial and rotational movement relative to a collar (12) filled with an acoustically coupling medium (14). Longitudinal waves are emitted into the coupling medium and the workpiece from a first transducer (22) and acoustic echoes are received thereby. From the coupling medium travel times between the transducer and the surface of the workpiece, a contour reconstruction apparatus (58) reconstructs the peripheral contour of the workpiece. The workpiece travel times are stored in a memory (92) until the longitudinal velocity of the acoustic wave in the workpiece is determined. Transducers (24, 26) emit and detect a Rayleigh wave which travels around the workpiece circumference. A divider (80) divides the workpiece circumference as determined by the contour reconstruction apparatus by the Rayleigh wave travel time to determine the Rayleigh wave acoustic velocity. A multiplier (82) multiplies the Rayleigh wave velocity by a preselected Rayleigh wave to longitudinal wave ratio to determine the velocity of the longitudinal wave in the workpiece. A second multiplier (100) multiplies the stored longitudinal wave travel times by the longitudinal wave velocit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.