Process control system using polarizing interferometer
US5286313A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1991 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Oct 31, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K15/046
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Fin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.