Electronic transducer
US5090248A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1990 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Jan 22, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An extensometer for measuring dimensional change comprises a pair of adjacent conductors (10) helically wound to form a bifilar one layer coil so as to have substantial elastic deformation. The coil is embedded in dielectric material (13) capable of similar elastic deformation whereby the extensometer has a large dynamic range. Elongation or deformations of the extensometer cause a change in electrical capacitance between the conductors which change in capacitance is monitored to measure the elongation or deformation. The conductors may have a rectangular cross-section with rounded corners to improve linearity of the graph of capacitance versus elongation. The extensometer has a length which is at least an order of magnitude greater than the cross-sectional dimension thereof. A method of constructing the extensometer includes forming the coil on a mandrel (11) removing the mandrel and immersing the coil in a container of liquid dielectric material until the liquid cures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.