Strain gauge apparatus
US3948089A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1973 |
| Grant date | Apr 6, 1976 |
| Priority date | — |
| Expiry date | Oct 12, 1993 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S173/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A specimen or in-service structural member in which strain is to be measured is fabricated as a unit which generates a signal in response to strain occurring in a given region of its surface. A film of piezoelectric material is deposited upon the surface in a manner providing a strong molecular bond between the specimen or member and the piezoelectric film. The film material is chosen from the class having a 6 mm type crystal lattice structure and is formed as a crystalline deposit with the c-axis perpendicular to the surface of the specimen or member. An arrangement of electrodes is provided for direct electrical coupling between spatially separated portions of the piezoelectric film. The electrodes form an output coupling for an electrical signal generated by the piezoelectrically active properties of the piezoelectric film in response to strain mechanically coupled from the substrate surface to the piezoelectric film through the molecular bond. In constructions in which there is a possibility of the electrode arrangement becoming short-circuited through minute vacancies present as imperfections in the piezoelectric film, an ultrathin film of insulating material is deposited adja…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.