Optical displacement transducer usable as an extensometer
US4690001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1985 |
| Grant date | Sep 1, 1987 |
| Priority date | — |
| Expiry date | Nov 13, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0647
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A non-contact, displacement transducer (optical extensometer), which is relatively simple to make and operate, and therefore low cost, utilizes 35 mm camera optics for the lens system and will focus a beam of light along a linear path of light sensitive elements representing a gauge length of a specimen or member. Flags or similar indicators that change the pattern of the light beam are mounted or marked on the specimen at two spaced loations. As the specimen is loaded, the flags will change in spacing, and, as shown, the change in the location of shadow will cause changes in the affected light sensitive elements which provide outputs that indicate displacement in the specimen. The sensing circuitry providing the output is compact and easily mounted within a module carrying the lens. The module may be mounted directly to a test specimen frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.